Computer application in business

Computer Application in Business
Md. Mokter Ali
Chapter-1
Introduction
Q-1: What is Computer? Briefly describe the classification of computer?
Computer: Computer is a machine that can be programmed to accept data (input), process it into
useful information (output), and store it away (in secondary storage device) for safekeeping or
later reuse
Most computers arc meant to be used by only one person at a time. Such computers are often
shared by several people (such as those in your school’s computer lab), but only one user can
work with the machine at any given moment.
The six primary types of computers in this category are
» Desktop computers
» Workstations
» Notebook computers
» Tablet computers
» Handheld computers
» Smart phones
These systems are all examples of personal computers (PCs)— a term that refers to any
computer system that is designed for use by a single person. Personal computers arc also called
nticroconipuicr*, because they are among the smallest computers created for people to use. Note,
however, that the term personal computer or PC is most often used to describe desktop
computers, which you w ill learn about in the following section.
Desktop Computers: The most common type of personal computer is the desktop computer—a
PC that is designed to sit on (or under) a desk or table. These are the systems you sec all around
you, in schools, homes, and offices, and they are the main focus of this book. Today's desktop
computers are far more powerful than those of just a few years ago, and are used for an amazing
array of tasks. Not only do these machines enable people to do their jobs with greater ease and
efficiency, but they can be used to communicate, produce music, edit photographs and videos,
play sophisticated games, and much more. Used by everyone from preschoolers to nuclear

physicists, desktop computers arc indispensable for learning, work, andgplay. Desktop PCs are a
familiar item In homes, schools, and workplaces.
Workstations: A workstation is a specialized, single-user computer that typically has more
power and features than a standard desktop PC . These machines are popular among scientists,
engineers, and animators who need a system with greater-than-average speed and the power to
perform sophisticated tasks. Workstations often have large, high-resolution monitors and
accelerated graphicshandling capabilities, making them suitable for advanced architectural or
engineering design, modeling, animation, and video editing.
Notebook Computers: Notebook computers, as their name implies, approximate the shape of an
8.5-by-ll-inch notebook and easily fit inside a briefcase. Because people frequently set these
devices on their lap, they are also called laptop computers. Notebook computers can operate on
alternating current or special battcrics. These amazing devices generally weigh less than eight
pounds, and some even weigh less than three pounds! During use, the computer’s lid is raised to
reveal a thin monitor and a keyboard. When not in use, the device folds up for easy storage.
Notebooks arc fully functional microcomputers; the people who use them need the power of a
full-size desktop computer wherever they go. Because of their portability, notebook PCs fall into
a category of devices Urheberrechllkrt Mg called mobile computers—systems small enough to
be carried by their user. Some notebook systems are designed to be plugged into a docking
station, which may include a large monitor, a full-size keyboard and mouse, or other devices.
Docking stations also provide additional ports that enable the notebook computer to be
connected to different devices or a network in the same manner as a desktop system.
Smart Phones: Some cellular phones double as miniature PCs. Because these phones offer
advanced features not typically found in cellular phones, they are sometimes Tablet PCs The
tablet PC is the newest development in portable, full-featured computers. Tablet PCs offer a ll
the functionality of a notebook PC, but they are lighter and can accept input from a special pen—
called a stylus or a digital pen—that is used to tap or write directly on the screen. Many tablet
PCs also have a built-in microphone and special software that accepts input from the user's
voice. A few models even have a fold-out keyboard, so they can be transformed into a standard
notebook PC. Tablet PCs run specialized versions of standard programs and can be connected to
a network. Some models also can be connected to a keyboard and a full-size monitor.
Handheld PCs: Handheld personal computers are computing devices small enough to fit in your
hand. A popular type of handheld computer is the personal digital assistant (PDA). A PDA is no
larger than a small appointment book and is normally used for special applications, such as
taking notes, displaying telephone numbers and addresses, and keeping track of dates or agendas.
Many PDAs can be connected to larger computers to exchange data. Most PDAs come with a
pen that lets the user write on the screen. Some handheld computers feature tiny built-in
keyboards or microphones that allow voice input. Many PDAs let the user access the Internet

through a wireless connection, and several models offer features such as cellular telephones,
cameras, music players, and global positioning systems.
Notebook computers have the power and features at desktop PCs but are called smart phones.
These features can include Web and c-mail access, special software such as personal organizers,
or special hardware such as digital cameras or music players. Some models even break in half to
reveal a miniature keyboard.
Q-2: Briefly describe the application of computer in business?
Almost every business uses computers to complete daily tasks. From making contact with clients
to inputting data for reports, computers allow businesses a more efficient way to manage affairs
when compared to traditional paper and manila folders. Businesses use a variety of different
types of computers such as desktops, laptops, servers, smartphones and tablets, depending on
their needs. With computers, employees are able to work anytime, anywhere.
Communication: Communication is key when gaining and maintaining clients and other
important contacts. Computers give businesses access to email, instant messaging and custom
customer contact systems. Computerized phone systems allow for automated support during off
hours and a virtual operator can quickly direct callers to the correct department for faster support.
Marketing: Computers allow businesses to create websites, stunning ads and complete
marketing campaigns. Marketing videos can be edited and custom ads created in-house with the
use of specialized software. Businesses can completely develop and manage websites with their
own servers or connect remotely to a third-party business to upload their latest content such as
articles, product images and blog posts.
Accounting: Accounting without computers presents a high risk for human error. Accounting
software allows businesses to simply input their financial data and instantly see gains and losses.
All necessary tax reports are available the moment the data is entered. Using computers for
invoicing, managing expenses and calculating payroll is vital for ensuring financial data is as
accurate as possible.
Storage: Instead of filing cabinets, businesses are able to store millions of files using computers
and servers. Data can be stored centrally for easy access from multiple computers or stored
locally for individual use. Computerized storage saves space and provides a far more efficient
organization strategy. With encryption, passwords and replace keys, data remains secure.
Documents and Reports: Most businesses have some sort of productivity software which
typically includes a word processor and spreadsheet application. These two programs allow
businesses to create reports, memos, tutorials and even colorful ads for company events.
Spreadsheet applications give businesses the chance to organize, manage and calculate both

numeric and alphabetic data. With charts and graphs, reporting becomes visual instead of text-
based.
Education: Businesses use computers to help educate employees on software, company policy,
standard procedures and safety. Instead of hiring teachers, computers can be used to educate
employees at their own pace or through an online webinar with live questions and answers. This
form of education fits the busy schedules of businesses without sacrificing the quality of the
education.
Research: From learning more about the competition to discovering what customers really want,
research isn't as difficult as it once was, thanks to computers. Search engines, forums, social
networks and industry specific websites provide businesses with a wealth of information and
research data.
Q-3: What is software? Describe the classification of software?
Software is a general term for the various kinds of programs used to operate computers and
related devices.
classification of software:
The two main classifications of software that all programs fit under are:
1. System software
2. Application software
Without software, most hardware would sit there doing nothing or perform specific tasks. To
make most hardware run we need to use software, and your task here is to select the correct type
of software for each job.
System software:
System software - software designed to operate the computer hardware and to provide a platform
for running application software.
Modern computers are complex machines involving many different parts. To keep it running
well you will need system software. System software will handle the smooth running of all the
components of the computer as well as providing general functionality for other programs to use,
tools to speed up the computer, tools to develop new software and programs to keep you safe
from attacks. There are several different types of system software that we will look at in more
detail very shortly:
Operating Systems are a collection of programs that make the computer hardware conveniently
available to the user and also hide the complexities of the computer's operation. The Operating
System (such as Windows 7 or Linux) interprets commands issued by application software (e.g.

word processor and spreadsheets). The Operating System is also an interface between the
application software and computer. Without the operating system, the application programs
would be unable to communicate with the computer.
Utility programs are small, powerful programs with a limited capability, they are usually
operated by the user to maintain a smooth running of the computer system. Various examples
include file management, diagnosing problems and finding out information about the computer
etc. Notable examples of utility programs include copy, paste, delete, file searching, disk
defragmenter, disk cleanup. However, there are also other types that can be separately installable
from the Operating System.
Library programs are a compiled collection of subroutines (e.g. libraries make many functions
and procedures available when you write a program)
Translator software (Assembler, Compiler, Interpreter)
Assembler translates assembly language programs into machine code (A binary code that a
machine can understand).
Compiler translates high level language code into object code (which is the machine language of
the target machine).
Interpreter analyses and executes a high-level language program a line at a time. Execution will
be slower than for the equivalent compiled code as the source code is analyzed line by line.
Application software:
Application software - software designed to help the user to perform specific tasks
Application software is designed for people like me and you to perform tasks that we consider
useful. This might be the ability of a scientist to work out statistical information using a set of
results, or someone who wants to play the latest computer game. There are several categories of
Application software that we'll look into shortly:
General purpose application software. Special purpose application software. Bespoke application
software Example: Software categories Place the following software into its correct category:
Computer Game - This is built for a human user, therefore it is application software Virus
Scanner - This is built to make the computer run better, therefore it is system software.
Q-4: Briefly describe the element of a computer system?
Elements of a Computer System:
A computer system is a set of six elements viz.:
(i) Hardware, (ii) Software, (iii) People, (iv) Procedures, (v) Data and (vi) Connectivity.

(i) Hardware: The physical components of a computer constitute its Hardware. These include
keyboard, mouse, monitor and processor. Hardware consists of input devices and output devices
that make a complete computer system. Examples of input devices are keyboard, optical scanner,
mouse and joystick which are used to feed data into the computer. Output devices such as
monitor and printer are media to get the output from the computer.
(ii) Software: A set of programs that form an interface between the hardware and the user of a
computer system are referred to as Software.
They are of six types:
(a) System software: A set of programs to control the internal operations such as reading data
from input devices, giving results to output devices and ensuring proper functioning of
components is called system software.
(b) Application software: Programs designed by the user to perform a specific function, such as
accounting software, payroll software etc.
(c) Operating system: A set of tools and programs to manage the overall working of a computer
using a defined set of hardware components is called an operating system. It is the interface
between the user and the computer system.
(d) Utility software: Certain special purpose programs that are designed to perform a
specialized task, such as functions to copy, cut or paste files in a computer, formatting a disk etc.
(e) Language processors: Special software to accept data and interpret it in the form of Machine
/Assembly language understandable by a computer. It also ensures the correctness of language
syntax and errors.
(f) Connectivity software: A set of programs and instructions to connect the computer with the
main server to enable sharing of resources and information with the server and other connected
computers.
(iii) People: The most important element of a computer system is its users. They are also called
live-ware of the computer system.
The following types of people interact with a computer system:
(a) System Analysts: People who design the operation and processing of the system.
(b) SystemProgrammers: People who write codes and programs to implement the working of
the system
(c) System Operators: People who operate the system and use it for different purposes. Also
called the end users.

(iv) Procedures: Procedure is a step by step series of instructions to perform a specific function
and achieve desired output.
In a computer system, there are three types of procedures:
(a) Hardware oriented procedure: It defines the working of a hardware component.
(b) Software oriented procedure: It is a set of detailed instructions for using the software.
(c) Internal procedure: It maintains the overall internal working of each part of a computer
system by directing the flow of information.
(v) Data: The facts and figures that are fed into a computer for further processing are called data.
Data is raw until the computer system interprets it using machine language, stores it in memory,
classifies it for processing and produces results in conformance with the instructions given to it.
Processed and useful data is called information which is used for decision making.
(vi) Connectivity: When two or more computers are connected to each other, they can share
information and resources such as sharing of files (data/music etc.), sharing of printer, sharing of
facilities like the internet etc. This sharing is possible using wires, cables, satellite, infra-red,
Bluetooth, microwave transmission etc.
Q-5: Mention the characteristics of different generation of computer?
First Generation (1940-1956) Vacuum Tubes
The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were
often enormous, taking up entire rooms. They were very expensive to operate and in addition to
using a great deal of electricity, the first computers generated a lot of heat, which was often the
cause of malfunctions.
First generation computers relied on machine language, the lowest-level programming language
understood by computers, to perform operations, and they could only solve one problem at a
time, and it could take days or weeks to set-up a new problem. Input was based on punched cards
and paper tape, and output was displayed on printouts.
The UNIVAC and ENIAC computers are examples of first-generation computing devices. The
UNIVAC was the first commercial computer delivered to a business client, the U.S. Census
Bureau in 1951.
Second Generation (1956-1963) Transistors
Transistors replace vacuum tubes and ushered in the second generation of computers. The
transistor was invented in 1947 but did not see widespread use in computers until the late 1950s.

The transistor was far superior to the vacuum tube, allowing computers to become smaller,
faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors.
Though the transistor still generated a great deal of heat that subjected the computer to damage,
it was a vast improvement over the vacuum tube. Second-generation computers still relied on
punched cards for input and printouts for output.
Second-generation computers moved from cryptic binary machine language to symbolic, or
assembly, languages, which allowed programmers to specify instructions in words. High-level
programming languages were also being developed at this time, such as early versions of
COBOL and FORTRAN. These were also the first computers that stored their instructions in
their memory, which moved from a magnetic drum to magnetic core technology.
The first computers of this generation were developed for the atomic energy industry.
Third Generation (1964-1971) Integrated Circuits
The development of the integrated circuit was the hallmark of the third generation of computers.
Transistors were miniaturized and placed on silicon chips, called semiconductors, which
drastically increased the speed and efficiency of computers.
Instead of punched cards and printouts, users interacted with third generation computers through
keyboards and monitors and interfaced with an operating system, which allowed the device to
run many different applications at one time with a central program that monitored the memory.
Computers for the first time became accessible to a mass audience because they were smaller
and cheaper than their predecessors.
Fourth Generation (1971-Present) Microprocessors
The microprocessor brought the fourth generation of computers, as thousands of integrated
circuits were built onto a single silicon chip. What in the first generation filled an entire room
could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the
components of the computer—from the central processing unit and memory to input/output
controls—on a single chip.
In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the
Macintosh. Microprocessors also moved out of the realm of desktop computers and into many
areas of life as more and more everyday products began to use microprocessors.
As these small computers became more powerful, they could be linked together to form
networks, which eventually led to the development of the Internet. Fourth generation computers
also saw the development of GUIs, the mouse and handheld devices

Fifth Generation (Present and Beyond) Artificial Intelligence:
Fifth generation computing devices, based on artificial intelligence, are still in development,
though there are some applications, such as voice recognition, that are being used today. The use
of parallel processing and superconductors is helping to make artificial intelligence a reality.
Quantum computation and molecular and nanotechnology will radically change the face of
computers in years to come. The goal of fifth-generation computing is to develop devices that
respond to natural language input and are capable of learning and self-organization.
Q-6: Write down the characteristics of computer?
Basic characteristics about computer are:
1. Speed: - As you know computer can work very fast. It takes only few seconds for calculations
that we take hours to complete. You will be surprised to know that computer can perform
millions (1,000,000) of instructions and even more per second.
Therefore, we determine the speed of computer in terms of microsecond (10-6 part of a second)
or nanosecond (10 to the power -9 part of a second). From this you can imagine how fast your
computer performs work.
2. Accuracy: - The degree of accuracy of computer is very high and every calculation is
performed with the same accuracy. The accuracy level is 7 determined on the basis of design of
computer. The errors in computer are due to human and inaccurate data.
3. Diligence: - A computer is free from tiredness, lack of concentration, fatigue, etc. It can work
for hours without creating any error. If millions of calculations are to be performed, a computer
will perform every calculation with the same accuracy. Due to this capability it overpowers
human being in routine type of work.
4. Versatility: - It means the capacity to perform completely different type of work. You may
use your computer to prepare payroll slips. Next moment you may use it for inventory
management or to prepare electric bills.
5. Power of Remembering: - Computer has the power of storing any amount of information or
data. Any information can be stored and recalled as long as you require it, for any numbers of
years. It depends entirely upon you how much data you want to store in a computer and when to
lose or retrieve these data.
6. No IQ: - Computer is a dumb machine and it cannot do any work without instruction from the
user. It performs the instructions at tremendous speed and with accuracy. It is you to decide what
you want to do and in what sequence. So a computer cannot take its own decision as you can.
7. No Feeling: - It does not have feelings or emotion, taste, knowledge and experience. Thus it
does not get tired even after long hours of work. It does not distinguish between users.

8. Storage: - The Computer has an in-built memory where it can store a large amount of data.
You can also store data in secondary storage devices such as floppies, which can be kept outside
your computer and can be carried to other computers.
9. Reduced Cost: - With the ever increasing advances being made in the state of the art. me cost
of computer equipments has dropped drastically over the years. Hardware costs have been
decreasing at an estimated annual rate of 25%. Thus. Companies that at one time could not
justify the cost of acquiring their own computer system may now find it not only feasible to
acquire a system. But cost effective as well.
Chapter-2
Input Device
Q-1: Briefly describe the classification of input hardware?
Following are few of the important input devices which are used in a computer:
Keyboard, Mouse , Joy Stick , Light pen , Track Ball , Scanner ,Graphic Tablet , Microphone
,Magnetic Ink Card Reader(MICR) , Optical Character Reader(OCR), Bar Code Reader, Optical
Mark Reader(OMR)
Keyboard: Keyboard is the most common and very popular input device which helps in
inputting data to the computer. The layout of the keyboard is like that of traditional typewriter,
although there are some additional keys provided for performing additional functions.
Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108
keys are also available for Windows and Internet.
Mouse: Mouse is most popular pointing device. It is a very famous cursor-control device having
a small palm size box with a round ball at its base which senses the movement of mouse and
sends corresponding signals to CPU when the mouse buttons are pressed. Generally it has two
buttons called left and right button and a wheel is present between the buttons. Mouse can be
used to control the position of cursor on screen, but it cannot be used to enter text into the
computer.
Joystick: Joystick is also a pointing device which is used to move cursor position on a monitor
screen. It is a stick having a spherical ball at its both lower and upper ends. The lower spherical
ball moves in a socket. The joystick can be moved in all four directions. The function of joystick
is similar to that of a mouse. It is mainly used in Computer Aided Designing(CAD) and playing
computer games.

Light Pen: Light pen is a pointing device which is similar to a pen. It is used to select a
displayed menu item or draw pictures on the monitor screen. It consists of a photocell and an
optical system placed in a small tube. When the tip of a light pen is moved over the monitor
screen and pen button is pressed, its photocell sensing element detects the screen location and
sends the corresponding signal to the CPU.
Track Ball: Track ball is an input device that is mostly used in notebook or laptop computer,
instead of a mouse. This is a ball which is half inserted and by moving fingers on ball, pointer
can be moved. Since the whole device is not moved, a track ball requires less space than a
mouse. A track ball comes in various shapes like a ball, a button and a square.
Scanner: Scanner is an input device which works more like a photocopy machine. It is used
when some information is available on a paper and it is to be transferred to the hard disc of the
computer for further manipulation. Scanner captures images from the source which are then
converted into the digital form that can be stored on the disc. These images can be edited before
they are printed.
Digitizer: Digitizer is an input device which converts analog information into digital form.
Digitizer can convert a signal from the television or camera into a series of numbers that could
be stored in a computer. They can be used by the computer to create a picture of whatever the
camera had been pointed at. Digitizer is also known as Tablet or Graphics Tablet because it
converts graphics and pictorial data into binary inputs. A graphic tablet as digitizer is used for
doing fine works of drawing and image manipulation applications.
Microphone: Microphone is an input device to input sound that is then stored in digital form.
The microphone is used for various applications like adding sound to a multimedia presentation
or for mixing music.
Microphone: MICR input device is generally used in banks because of a large number of
cheques to be processed every day. The bank's code number and cheque number are printed on
the cheques with a special type of ink that contains particles of magnetic material that are
machine readable. This reading process is called Magnetic Ink Character Recognition (MICR).
The main advantages of MICR is that it is fast and less error prone.
OCR: OCR is an input device used to read a printed text. OCR scans text optically character by
character, converts them into a machine readable code and stores the text on the system memory.
Bar Code Reader: Bar Code Reader is a device used for reading bar coded data (data in form of
light and dark lines). Bar coded data is generally used in labelling goods, numbering the books
etc. It may be a hand held scanner or may be embedded in a stationary scanner. Bar Code Reader
scans a bar code image, converts it into an alphanumeric value which is then fed to the computer
to which bar code reader is connected.

Optical Mark Reader(OMR): OMR is a special type of optical scanner used to recognize the
type of mark made by pen or pencil. It is used where one out of a few alternatives is to be
selected and marked. It is specially used for checking the answer sheets of examinations having
multiple choice questions.
Q-2: What is terminal? Describe different types of terminal?
Data input-output device, usually made up of a monitor (display), keyboard, mouse, or touch
screen. It is the point at which a user is connected to and communicate with a computer or a
website through a network. Three basic types of terminals are (1) Dumb terminal: has no built-in
data processing capabilities and serves only to send and receive data, (2) Smart terminal: has
limited data processing capabilities, and (3) Intelligent terminal: has substantial data processing
capabilities due to inbuilt processor and memory.
Dumb Terminal: A dumb terminal is a very simple monitor with very little processing power
and features. It does not have the ability to process escape sequences such as clearing a line,
clearing the screen or controlling the cursor position. It is dubbed as a glass Teletype as it has the
same limited functionality of one. It is usually paired with a keyboard and sometimes a mouse to
allow the user to input commands and data.
Smart Terminal: Smart terminal is a monitor that has its own processor for special features,
such as bold and blinking characters.
Intelligent Terminal: Intelligent terminal A device with some processing capability, by means
of which information may be transferred to and from a larger processing system. The device is
often a combination of a display and keyboard with at least one built-in microprocessor to
provide facilities such as editing and prompts for the operator. Modern application terminals for
banking, retail, and industrial data collection are other examples of intelligent terminals.
Q-3: What is barcode reader? Write down the application of barcode reader in business?
Barcode Reader: A barcode reader is a hand-held or stationary input device used to capture and
read information contained in a barcode. A bar-code reader consists of a a lens, light source and
a light sensor which translates optical impulses into electrical ones. Moreover, nearly all barcode
readers consists of a decoder circuitry that analyzes the barcode’s image data provided by the
sensor and sends the barcode’s content to the scanner’s output port.
Application of barcode reader in business: Barcodes are often overlooked as a method for
cutting costs and saving time. A valuable and viable choice for businesses looking to improve
efficiency and reduce overhead, barcodes are both cost-effective and reliable.

Barcodes eliminate the possibility of human error: The occurrence of errors for manually
entered data is significantly higher than that of barcodes. A barcode scan is fast and reliable, and
takes infinitely less time than entering data by hand.
Using a barcode system reduces employee training time: It takes only minutes to master the
hand-held scanner for reading barcodes. Furthermore, employees do not have to gain familiarity
with an entire inventory or pricing procedure. This also makes employee training less expensive,
since they do not have to be paid for extra training time, and another employee does not have to
be compensated for training them.
Barcodes are inexpensive to design and print: Generally they cost mere pennies, regardless of
their purpose, or where they will be affixed. They can be customized economically, in a variety
of finishes and materials.
Barcodes are extremely versatile: They can be used for any kind of necessary data collection.
This could include pricing or inventory information. Additionally, because barcodes can be
attached to just about any surface, they can be used to track not only the products themselves, but
also outgoing shipments and even equipment.
Inventory control improves: Because barcodes make it possible to track inventory so precisely,
inventory levels can be reduced. This translates into a lower overheard. The location of
equipment can also be tracked, reducing the time spent searching for it, and the money spent
replacing equipment that is presumed lost.
Barcodes provide better data: Since one barcode can be used for inventory and pricing
information, it is possible to quickly obtain data on both. Furthermore, barcodes can be
customized to contain other relevant information as needed. They provide fast, reliable data for a
wide variety of applications.
Data obtained through barcodes is available rapidly: Since the information is scanned
directly into the central computer, it is ready almost instantaneously. This quick turnaround
ensures that time will not be wasted on data entry or retrieval.
Barcodes promote better decision making: Because data is obtained rapidly and accurately, it
is possible to make more informed decisions. Better decision making ultimately saves both time
and money.
Both inexpensive and user-friendly, barcodes provide an indispensable tool for tracking a variety
of data, from pricing to inventory. The ultimate result of a comprehensive barcoding system is
reduction in overhead.

Q-4: What is MICR? What is the application of MICR in business?
MICR: MICR is an acronym for Magnetic Ink Character Recognition; it refers to the
formulation of toner used to print the specialized font at the bottom of checks and other
negotiable documents. Unlike regular laser toner, MICR toner contains iron oxide, which is
required by the Federal Reserve to make the check-clearing process more efficient.
Application of MICR in business: Magnetic ink contains a special metal powder with magnetic
properties. When this ink issued to write or print text on paper, the texts are human readable or
can be read special device called the magnetic ink character recognition (MICR) reader, which
also reproduces the characters into the computer.
The reading speed of MICR is faster than OCR. Magnetic ink readers are largely used in banks
to read from a cheque, the cheque number, the bank number, the branch number and the
customer’s account number.
MICR characters, such as those located on the bottom of a check that represent the bank routing
number, check number and account number are inscribed on checks with magnetic ink when the
checks are first printed.
MICR text uses a unique typeface, which gives it a distinct appearance that is readily
recognizable by eye. The characters can still be read by the computer even after being
overwritten with ordinary ink or handle with dirty hands.
Smaller units of MICR are used by many businesses to deposit paper checks remotely. To make
a remote deposit using an MICR reader the check is scanned and then the check data is
transmitted to the bank electronically for payment.
There are also MICR readers incorporated in most new ATM machines today to enable the
MICR information located on checks inserted into the ATM machine to be read at the time of the
deposit.
The advantages of magnetic ink character recognition include: accuracy, difficult to forge, can be
read easily and speed or reading.
Q-5: What is RFID? Write down the application of RFID in business?
RFID stands for Radio-Frequency IDentification. The acronym refers to small electronic devices
that consist of a small chip and an antenna. The chip typically is capable of carrying 2,000 bytes
of data or less. The RFID device serves the same purpose as a bar code or a magnetic strip on the
back of a credit card or ATM card; it provides a unique identifier for that object. And, just as a
bar code or magnetic strip must be scanned to get the information, the RFID device must be
scanned to retrieve the identifying information.

Application of RFID in business: This process grounds the RFID program in the reality of your
specific enterprise. Creating a realistic business model that represents both the status quo and the
economic impacts of RFID is essential.
Cost reduction: Cost reduction The cost reduction value case is a target area of many consumer
packaged goods (CPG) companies, retailers.
Increase revenue: Both large and small retailers and manufacturers are developing RFID
deployments to drive sales. The utilization of RFID empowers these companies to design
innovative solutions with tangible benefits, including: • Reduced out-of-stocks • Improved order
fill rates • Reduced shrinkage • Improved inventory turns • Enhanced in-store customer support.
Counterfeit product shielding: Quality manufacturers across the globe are losing sales, profits
and their quality image from the expanding flow of counterfeit products. Equally important,
counterfeits of many products (such as pharmaceuticals, currency, passports and aircraft parts)
represent a safety and security hazard for customers across the globe.
Shrinkage, theft and diversion prevention: High-value consumer and industrial products face
the large risk of theft and diversion. RFID has shown considerable progress in: • Identifying theft
and diversion at the shelf level • Identifying theft and diversion points in the supply chain.
Competitive advantage: Any business case or profit improvement program is intertwined with a
company’s business goals and competitive advantage. Understanding competitive advantage can
be reduced to a simple question: are we better than our peers in key performance areas? Several
leading companies believe that RFID is the key to increasing competitive advantage. Sources of
advantages include:
• To increase distribution center productivity
• To increase yield per end user, customer or site
• To create a flexible, adaptive supply chain
• To create a cost advantage in logistics
Q-6: What are the differences between OCR & OMR?
OMR is Optical Marks Recognition. Marks or markings is given in a particular form by the user
by pen or pencil. On the hardware side there is a highspeed Mark Recognition Scanner with
software support. Different values are given for different markings. The scanner quickly scans
the form and convert the markings into data, which inturn can be used for various purposes. ie;
instead of writing a form in a bad handwritting, the person entering the data struggling with that,
and entering wrong data, the OMR method is more reliable for the user, what you marked is
what you get.

OCR is Optical Character Recognition. A printed matter is scanned with a high resolution
scanner as an image. On the software side the software recognises Letter 'A' as A and stores the
information. Likewise this regognition is done on the whole image, converting it into a document
in the editable format. Particularly useful for reprinting an old book with editings where no
softcopy is available, and for many other purposes depending on the need.
Chapter-3
Output Device
Q-1: Write down the name of softcopy and hardcopy output hardware?
Soft copy output devices output information to a computer monitor or other temporary output
device. Soft copy output
COMPUTER MONITORS/DISPLAYS
The computer monitor, like a television, displays computer output for a user to view. The
monitor has various names: screen or video display unit. When purchasing a computer monitor,
the following features are importan
Technology
AUDIO OUTPUT DEVICES: Voice (audio) output devices include those devices that output
voice or voice-like sounds and those that output music and other sound. This includes head
phones, speakers enabled by sound cards.
VOICE OUTPUT DEVICES: A voice output device convert digital data into speech-like
ses actual human voices
speaking words to provide a digital database of words that can
synthesis: uses a set of forty basis speech sounds (called phonemes, the basic of all speech
English) to electronically create any word. Human voices are not used to make up a database of
words: the computer converts stored text in voices.
SOUND OUTPUT DEVICES: Sound output devices produce digitized sounds, ranging from
beeps and chirps to music. All these sounds are nonverbal such as the screeching of a car. Sound
output requires the necessary software and sound card or digital audio circuit board.

VIDEO OUTPUT: Video output is the output of motion video to be viewed by a computer user.
Examples of video output devices or applications
.
Q-2: What are the differences between impact and nonimpact?
Impact printer / Dot-matrix Printer Non impact Printer / Laser Printer
1. It prints characters or images by striking print
hammer or wheel against an inked ribbon.
1. It prints characters and images without
striking the papers.
2. Its speed is slower. 2. Its speed is faster.
3. Its printing quality is lower. 3. Its printing quality is higher.
4. It normally uses continuous paper sheet. 4. Its normally uses individual paper sheet.
5. It generates noise during printing. 5. It does not generate noise during printing.
6. It uses inked ribbon for printing. 6. It uses toner or cartridge for painting.
7. It is less expensive. 7. It is more expensive.
8. Dot matrix is an impact printer. 8. Laser printer is a non-impact printer.
Q-3: Briefly describe the classification of computer?
Basedon the operating principles, computers can be classified into one of the following
types: -
A. Digital Computers
B. Analog Computers
C. Hybrid Computers
A. Digital Computers: - Operate essentially by counting. All quantities are expressed
as discrete or numbers. Digital computers are useful for evaluating arithmetic expressions and
manipulations of data (such as preparation of bills, ledgers, solution of simultaneous equations
etc)
B. Analog Computers:- An analog computer is a form of computer that uses the
continuously changeable aspects of physical phenomena such as electrical, mechanical,
orhydraulic quantities to model the problem being solved. In contrast, digital computers
represent varying quantities symbolically, as their numerical values change.

C. Hybrid Computers:- are computers that exhibit features of analog computers and
digital computers. The digital component normally serves as the controller and provides logical
operations, while the analog component normally serves as a solver of differential equations.
CLASSIFICATION BASED ON AREA OF APPLICATION
Modern computers depending upon their applications are classified as: -
a. Special Purpose Computers
b. General Purpose Computers
a.) Special Purpose Computers: - A special purpose computer is designed only to meet the
requirements of a particular task or application. The instructions needed to perform a particular
task are permanently stored into the internal memory, so that it can perform the given task on a
single command. It therefore doesn’t posses unnecessary options and is less expensive.
b) General Purpose Computers: - A General Purpose computers are designed to meet the
needs of many different applications. In these computers, the instructions needed to perform a
particular task are wired permanently into the internal memory. When one job is over,
instructions for another job can be loaded into the internal memory for processing. This, a
general purpose machine can be used to prepare pay-bills, manage inventories, print sales report
and so on.
CLASSIFICATION BASED ON AREA OF APPLICATION
Modern computers depending upon their applications are classified as: -
a. Special Purpose Computers
b. General Purpose Computers
a.) Special Purpose Computers: - A special purpose computer is designed only to meet the
requirements of a particular task or application. The instructions needed to perform a particular
task are permanently stored into the internal memory, so that it can perform the given task on a
single command. It therefore doesn’t posses unnecessary options and is less expensive.
b) General Purpose Computers: - A General Purpose computers are designed to meet the
needs of many different applications. In these computers, the instructions needed to perform a
particular task are wired permanently into the internal memory. When one job is over,

instructions for another job can be loaded into the internal memory for processing. This, a
general purpose machine can be used to prepare pay-bills, manage inventories, print sales report
and so on.
Q-4: What are factors you should considering before buying printer and Monitor?
If you’re buying a new printer, you have a great opportunity to start over with a machine that’s
better suited to your needs—and your budget. But it’s not always easy to find the right machine
for you—and with the way manufacturers charge for ink and other peripherals, a great deal isn’t
always as great as it seems once you factor in the ink cartridges. Here are a few factors to
consider when buying a new printer to ensure you get the best deal on the best machine.
Your budget: Inkjet printers and laser printers are sold under different business models.
Manufacturers sell inkjet printers cheaply, then make money when customers return to buy
overpriced ink. Laser printers cost more up front, but they tend to be more economical over time.
A laser printer’s toner cartridge may be able to print up to 8,000 pages before it runs out.
Compare that to an inkjet printer, which might print as little as 200 pages before the cartridges
run dry.
The type of printing you’re doing: Printers nowadays can be highly specialized to a certain
type of use. If you’re planning to print a lot of family photos, you’ll need a different type of
printer than if you’re planning on printing mostly business documents in black and white or
brochures for your home business. If you need colour printing, a colour inkjet is probably your
best bet unless you have the budget for a colour laser. Black-and-white printing can often be
done more economically on a laser printer.
The amount of printing you’re doing: Studies have shown that laser printers are much more
economical when printing in volume—if you’re probably going ot print more than 100 pages per
month, a laser printer may be a better bet for you in the long term even though they cost more up
front. An inkjet printer is typically cheaper, but the cost in ink is much higher. Still, these can be
good machines for more limited printing.
The space you have available: Printers come in all shapes and sizes, from tiny personal use
machines to husky business printers designed for high-volume use and more complex graphics.
If you have a small area for your printer, you may be limited in the type of printer you can buy.
If space is an issue, go to the store with measurements in hand to make sure you get a machine
that fits your space.
Your computer: Most printers work with both Macs and PC’s. But some aren’t readily
compatible with certain operating systems—Linux, for example, requires specialized drivers that
can be hard to find. In addition, some printers only connect to computers via a USB port—
which not all computers come equipped with. If your computer doesn’t have a USB, look for a
printer that connects via a parallel port.

The cartridge situation: When considering budget, most people don’t factor in the cost of
consumables—especially printer ink cartridges. But many inkjet manufacturers design their
business models so that the bulk of their profit is made from cartridge sales. Original cartridges
can be overpriced, and they also often come equipped with technology that ensures you use up
the cartridge faster.
To make sure you’re getting the best deal, first take a look at the cost of cartridges and factor that
into the cost of the printer. You may find that cheap printer has some hidden expenses. Ask the
salesperson how many pages the cartridges can print before they run out—a cheap cartridge may
only have a few hundred pages in it, making it more expensive than you realize.
Avoid printers that have three-in-one cartridges—these make you replace the cartridge when just
one colour is empty, resulting in a lot of wasted ink. And if you can, avoid cartridges with Smart
Chips—these often make you replace cartridges after a certain expiration date or before you’ve
run out of ink entirely. Last, check the availability of third-party remanufactured and recycled
cartridges. The more widely available these are for your brand, the more likely you’ll be able to
save money by buying generic cartridges.
Finding the right printer takes time—and you’ll often have to look beyond the sticker price to
figure out whether or not you’re really getting the best deal. But a little research can go a long
way, and in the end you’ll find the time you spent is worth it.
Factors you should considering before buying Monitor: There’s no doubt – our world has
become increasingly driven by computer and information technology, in a relatively short
amount of time too. Just 20 years ago, only a handful of workers in an office had a computer at
their desk. Today, most occupations use computers in some form or fashion.
When researching monitors for you and your staff, there are several factors you need to consider
in order to get the right one. Continue reading for 8 of the most common…
1. Size: By size, we mean the diagonal measurement of the screen itself. Back in the day,
meaning the 90s, bulky CRT monitors in the 14- and 15-inch range were the norm. But oh how
times have changed. With flat LCD monitors becoming more commonplace, it’s pretty common
to find a 24-, 27-, or even a 30-inch monitor for a reasonable price.
2. Resolution: By resolution, we mean the number of pixels a monitor has to display an image.
A monitor’s pixel count consists of two numbers (e.g. 2560-by-1440), with the first one being
the number of horizontal pixels and the second being the vertical pixel count. A smaller count,
like a 1920-by-1080 (common on 24” monitors), means the pixels are more spread out.
Therefore, every icon, letter and window appears larger on the screen.
If you’re buying a monitor for maximum display capacity, be sure you choose one with a larger
pixel count.

3. Aspect Ratio: The monitor’s aspect ratio is defined as the ratio between the display area’s
width and height. The most common aspect ratios are either a 16:9 or 16:10. A 16:9 screen for
example is good for playing widescreen, high-def content. The 16:10 has more vertical pixels,
which makes it ideal for looking at large spreadsheets and the like.
4. Backlighting: LED backlighting has become more commonplace with today’s computer
monitors. Unlike cold cathode fluorescent lamps (CCFLs), the LED screens are thinner, generate
less heat, and warm up much faster. They also use less power and do not require mercury, unlike
the CCFLs of yesteryear.
5. Twisted nematic (TN) or In-plane switching (IPS): LCD monitors are available in two
different panel types. TN is the least expensive and most common, while the IPS panels are
higher-quality, yet more expensive. IPS is often found in professional-grade displays due to its
wider viewing angles, ability to display more colors and other attributes important to
professional photographers, artists and graphic designers.
6. Video input: This really depends on the age of your computer. If it’s older, you’ll need an
analog, or VGA. Newer computer models use a digital connection for the monitor (e.g. DVI,
HDMI or DisplayPort). Most monitors come with one analog and one digital video input.
7. Ergonomic flexibility: The stand the monitor sits on is almost as important as the technical
aspects described above. You don’t want to have to put your beautiful new monitor on top of a
stack of books to be able to use it without hurting your neck. Many displays are really limited in
that they only allow you to tilt the monitor back a few degrees. More advanced ones though
allow you to tilt, adjust the height, swivel left and right and other neat things.
8. Should I buy one screen or two? This really comes down to your personal preference. For
example, some will use one monitor for spreadsheets and documents and the other for the
Internet, chat windows and other utilities. If you plan to have two monitors, try to find one with a
thin bezel, or physical piece bordering the screen. This is especially important if you plan to have
info spanning both screens.
NOTE – BE SURE YOUR COMPUTERS’ GRAPHIC CARD SUPPORTS TWO MONITORS!!
Many of the factors not discussed here really boil down to personal preference, what the monitor
will be used for, and of course your budget. If you’ll only be using a monitor for an hour or two
a day, a less expensive one may be okay. But if you’ll be using the machine all day, it may be
wise to spend the extra money for a better quality monitor.

Q-5: What are the advantages of flat-panel monitor over CRT monitor?
Ever-so-common output staple is going away, and not many people are going to miss it. That
would be the big, clunky, desk-hogging tube monitor called the CRT (for cathode-ray tube). It's a
flat-panel world now. Steve still has a certain fondness for CRTs, but he also has a rather large
home office; when he can't figure out what one would put in the gained space behind a flat-panel,
Angela informs him that most of us put our walls there.
Those big CRT monitors also produce a lot of heat, which wastes energy. And they deteriorate
over time, so that a tube that looked pretty good five years ago probably doesn't look so hot
today. And they weigh a lot! In fact, their only theoretical advantage is picture quality--the
viewing angle is wide, so you don't have to sit right in front to see it--and, for gamers, CRTs'
faster refresh speeds.
But both of those advantages go away with modern flat-panel monitors. Unless you're a graphics
professional who needs the particularly accurate color you get on a big tube, you're going to
prefer one of these skinny guys. (Or unless you're a professional cheapskate, says Steve, an
amateur cheapskate who's extremely dedicated to his craft.) Tube monitors are cheap, cheap,
cheap. But flat panels are getting there; prices have dropped about as much as Seinfeld stars'
popularity, and the premium you'll pay to bump up to a flat panel isn't more than maybe a couple
of hundred bucks, if that.
So the Duo are for once in agreement: It's time for you to look into (Ha! Is funny! Laugh!) a flat-
panel monitor. But there are a few things worth knowing before you hit the stores. For openers,
understand that unlike with CRTs, screen-dimension numbers are honest for flat panels. With a
tube, you always end up with less than the official count. The rule of thumb for CRTs is to
subtract two inches from the stated tube size to get the same size flat-panel screen. For instance,
a 19-inch tube would be equivalent to a 17-inch flat panel.
Why is bigger better? In general, the bigger the screen, the more pixels you get, which lets you
cram more on screen at once. A 15-inch flat panel gives you a resolution of 1024 by 768 pixels.
A 17-inch monitor gives you a resolution of 1280 by 1024--two-thirds more stuff visible on the
screen at once. But there's a catch: At least for now, 19-inch monitors gives you the same
number of pixels as 17-inchers. So you don't see more info, you see everything a little bigger
and, to Steve's eyes, usually a little grainier. If your vision's bad, the 19-inchers are probably the
way to go.
But the Duo agree that for now, the 17-inch models are usually the best deal. You can get one for
about $250, which isn't much more than you'll spend for a 15-inch model--and it's several
hundred dollars less than you'd lay out for a 19-inch model. Now, just to confuse things, monitor
makers are adding wide-screen models, which have two big advantages: They make it relatively
simple to open two windows side-by-side (say for comparing prices while you're shopping

online), and they're also handy for watching wide-screen movies. They're cheaper than ever, but
they're not what anybody would call cheap ... yet.
If you really need a lot of screen space, and not for DVDs, consider doing what a lot of
professionals have been doing for years, especially in the Mac world: Use multiple monitors
mounted side-by-side. Increasingly, monitor makers are offering designs with narrow frames so
you can place units closer than ever to each other. You'll need to install an extra video card for
each monitor, or get a special video card that can handle multiple units. And it turns out that
three is a better number of monitors than two, because Windows is too stupid to do things like
figure out that you really don't want neatly centered dialog boxes that sit on the border between
the screens. Macs handle this multiple-monitor thing a lot better, but even Windows users who
need a lot of screen space will find that multiple monitors can provide it much more cheaply than
buying a single big one.
Chapter-4
CPU
Q-1: What is CPU? What are the functions of ALU and control unit?
The central processing unit (CPU) is the unit, which performs most of the processing inside a
computer. To control instructions and data flow to and from other parts of the computer, the CPU
relies heavily on a chip set, which is a group of microchips located on the motherboard.
functions of ALU : An arithmetic logic unit (ALU) is a digital circuit used to perform arithmetic
and logic operations. It represents the fundamental building block of the central processing unit
(CPU) of a computer. Modern CPUs contain very powerful and complex ALUs. In addition to
ALUs, modern CPUs contain a control unit (CU).
Most of the operations of a CPU are performed by one or more ALUs, which load data from
input registers. A register is a small amount of storage available as part of a CPU. The control
unit tells the ALU what operation to perform on that data and the ALU stores the result in an
output register. The control unit moves the data between these registers, the ALU, and memory.
How an ALU Works: An ALU performs basic arithmetic and logic operations. Examples of
arithmetic operations are addition, subtraction, multiplication, and division. Examples of logic
operations are comparisons of values such as NOT, AND, and OR.
All information in a computer is stored and manipulated in the form of binary numbers, i.e. 0 and
1. Transistor switches are used to manipulate binary numbers since there are only two possible
states of a switch: open or closed. An open transistor, through which there is no current,
represents a 0. A closed transistor, through which there is a current, represents a 1.

Operations can be accomplished by connecting multiple transistors. One transistor can be used to
control a second one in effect, turning the transistor switch on or off depending on the state of
the second transistor. This is referred to as a gate because the arrangement can be used to allow
or stop a current.
The simplest type of operation is a NOT gate. This uses only a single transistor. It uses a single
input and produces a single output, which is always the opposite of the input. This figure shows
the logic of the NOT gate.
How a NOT gate processes binary data
alu not gate
Other gates consist of multiple transistors and use two inputs. The OR gate results in a 1 if either
the first or the second input is a 1. The OR gate only results in a 0 if both inputs are 0. This
figure shows the logic of the OR gate.
How an OR gate processes binary data
alu or gate
The AND gate results in a 1 only if both the first and second input are 1s. This figure shows the
logic of the AND gate.
How an AND gate processes binary data
alu and gate
The XOR gate, also pronounced X-OR gate, results in a 0 if both the inputs are 0 or if both are 1.
Otherwise, the result is a 1. This figure shows the logic of the XOR gate.
How an XOR gate processes binary data.
alu xor gate
The various gates sound a little abstract, but remember that a computer only processes binary
data. When you follow the binary logic of these operations, you are starting to think like a
computer.
Functions of control unit: CPU is partitioned into Arithmetic Logic Unit (ALU) and Control
Unit (CU).
ol unit is to generate relevant timing and control signals to all operations
in the computer.
and memory and peripherals

The control unit directs the entire computer system to carry out stored program instructions.
nicate with both the arithmetic logic unit (ALU) and main
memory.
rithmetic logic unit that which logical or arithmetic operation is
to be performed.
-ordinates the activities of the other two units as well as all peripherals and
auxiliary storage devices linked to the computers.
Q-2: What is computer bus? Describe different types of computer bus?
BUS: A bus, in computing, is a set of physical connections (cables, printed circuits, etc.) which
can be shared by multiple hardware components in order to communicate with one another.
The purpose of buses is to reduce the number of "pathways" needed for communication between
the components, by carrying out all communications over a single data channel. This is why the
metaphor of a "data highway" is sometimes used.
TYPES of BUS: The preferred method for data/information transferbetween system components
is by a common data bus.Where point-to-point data transfer is required, thedigital format is the
preferred method. GeneralRequirements for Electronic Equipment Specifications,MIL-STD-
2036 series, provides a list of the industryaccepted standard internal data buses. They
includethe standard and the interface as follows:IEEE 696—IEEE Standard 696
InterfaceDevices, S-100IEEE 896.l—IEEE Standard Backplane BusSpecification for
Multiprocessor Architecture,Future BusI E E E 9 6 1 — S t a n d a r d f o r a n 8 - b i
tMicrocomputer Bus System, STD BusIEEE 1014—Standard for a Versatile BackplaneBus,
VMEbusIEEE 1196—Standard for a Simple 32-BitBackplane Bus, NuBusIEEE 1296—
Standard for a High-PerformanceSynchronous 32-Bit Bus, Multibus IIAll computers use three
types of basic buses. Thename of the bus is generally determined by the type ofsignal it is
carrying or the method of operation. Wegroup the buses into three areas as you see them in their
most common uses. They are as follows: Control (also called timing and control bus),
address, and data (also called a memory bus) buses Instruction (I), Operand (O), Input/Output
Memory (I/O MEM) or Input/Output Controller (IOC), and Computer Interconnection System
(CIS) Time multiplexed bus
Control Bus: The control bus is used by the CPU to direct and monitor the actions of the other
functional areas of the computer. It is used to transmit a variety of individual signals (read,
write, interrupt, acknowledge, and so forth) necessary to control and coordinate the
operations of the computer. The individual signals transmitted over the control bus and their
functions are covered in the appropriate functional area description.

Address Bus: The address bus consists of all the signals necessary to define any of the possible
memory address locations within the computer, or for modular memories any of the possible
memory address locations within a module. An address is defined as a label, symbol, or other set
of characters used to designate a location or register where information is stored. Before data or
instructions can be written into or read from memory by the CPU or I/O sections, an address
must be transmitted to memory over the address bus. Data Bus The bidirectional data bus,
sometimes called the memory bus, handles the transfer of all data and instructions between
functional areas of the computer.
The bidirectional data bus can only transmit in one direction at a time. The data bus is used
to transfer instructions from memory to the CPU for execution. It carries data (operands) to and
from the CPU and memory as required by instruction translation. The data bus is also used
to transfer data between memory and the I/O section during input/output operations. The
information on the data bus is either written into
Q-3: What factors determine the speedof computer?
Factors Affecting Processing Speed
In the modern days competitive world, quick result is the most. We are moving so fast in our day
to day life that we want to get results quickly. We use computer to perform various certain task
quickly & accurately so that we can get our work done. But there are many factors that could
affect the computer system & give us very poor result beyond our expectation. Some of the
Factor that can affect our computer system are discussed below:
 Registers
 RAM
 The System Clock
 The Bus
 Cache Memory
1. Registers: The CPU contains of small memory areas:called registers,which store data and
instructions while the CPU processes them. The size of the registers determines the amount of
data with which the computer can work at a one time. Today most PC`s have 32-bit
registers,mean the CPU can process four bytes data at one time.Register sizes are rapidly
growing to 64 bits.
2. RAM: The amount of RAM in a PC has a direct affect on the system`s speed. The more RAM
a PC has.the more program instructions and data can be held in memory,which is faster than
storage on disk. If a PC does not have enough memory to run a program,it must move data

between RAM and the hard disk frequently.This process called swapping,can greatly slow a
PC`s performance.
3. The System Clock: The computer`s system clock sets the pace the CPU by using a vibrating
quartz crystal. A single "tick" of the clock is the time required to turn a transistor off and back
on.This is called a clock cycle. Clock cycles are measured in Hertz(Hz),a measure of cycles per
second.If a computer has a clock speed of 300 MHz, then its system clock"ticks" 300 million
times every seconds. The faster a PCs clock runs,the more instructions the PC can execute each
second.
4. The Bus: A bus is a path between the components of a computer.Data and instructions travel
along these paths. The data bus width determines how many bits can be transmitted between the
CPU and other devices. The address buss runs only between the CPU and RAM, and carries
nothing but memory addresses for the CPU to use. Peripheral devices are connected to the CPU
by an expansion bus.
5. Cache Memory: Cache memory is high-speed memory that holds the most recent data and
instructions that have been loaded by the CPU. Cache is located directly on the CPU or between
the CPU and RAM,making it faster than normal RAM. CPU-resident cache is called Level-1
(L1)cache.External cache is called Level-2 (L2) cache. The amount of cache memory has a
tremendous impact on the computer`s speed.
Q-4: What is Machine Cycle?
Machine cycle: The steps performed by the computer processor for each machine language
instruction received. The machine cycle is a 4 process cycle that includes reading and
interpreting the machine language, executing the code and then storing that code.
Four steps of Machine cycle
1. Fetch - Retrieve an instruction from the memory.
2. Decode - Tranlate the retrieved instruction into a series of computer commands.
3. Execute - Execute the computer commands.

4. Store - Sand and write the results back in memory.
Instruction cycle
 The sequence of operations that the cpu has to carry out while execution is called
instruction cycle.
 1:- Read an Instruction
 2:- Decode the instruction
 3:- Find the address of operand
 4:- retrieve an operand
 5:- perform desired operation
 6:- find the address of destination
 7:- store the result into the destination
Chapter-5
Memory
Q-1: What are the differences between primary and secondary memory?
Primary Memory Secondary Memory
These are semiconductor memories. These are magnetic and optical memories.
They are characterized as volatile random
access memories (RAM) or non-volatile
memories (ROM). They are non-volatile.
They contain program and data that is
currently being used by micro processor. These are used to for bulk storage.
These memories are fast enough to interact
with the microprocessor. Slower than primary memories.

Also known as Main Memory
Also known as Backup Memory or Auxiliary
Memory. E.g. Tapes, Floppies, Hard Discs,
CD ROMs, DVDs
Q-2: What is cache memory? Why is it used in computer system?
Cache memory: Cache memory is a small-sized type of volatile computer memory that provides
high-speed data access to a processor and stores frequently used computer programs,
applications and data. It stores and retains data only until a computer is powered up.
A CPU cache is a cache used by the central processing unit of a computer to reduce the average
time to access memory. The cache is a smaller, faster memory which stores copies of the data
from the most frequently used main memory locations. As long as most memory accesses are
cached memory locations, the average latency of memory accesses will be closer to the cache
latency than to the latency of main memory.
When the processor needs to read from or write to a location in main memory, it first checks
whether a copy of that data is in the cache. If so, the processor immediately reads from or writes
to the cache, which is much faster than reading from or writing to main memory.
Each location in each memory has a datum (a cache line), which in different designs ranges in
size from 8 to 512 bytes. The size of the cache line is usually larger than the size of the usual
access requested by a CPU instruction, which ranges from 1 to 16 bytes. Each location in each
memory also has an index, which is a unique number used to refer to that location. The index for
a location in main memory is called an address. Each location in the cache has a tag that contains
the index of the datum in main memory that has been cached. In a CPU's data cache these entries
are called cache lines or cache blocks.
Most modern desktop and server CPUs have at least three independent caches: an instruction
cache to speed up executable instruction fetch, a data cache to speed up data fetch and store, and
a translation lookaside buffer used to speed up virtual-to-physical address translation for both
executable instructions and data.
Q-3: Write down the application of optical disks?
An optical disk drive (ODD) uses a laser light to read data from or write data to an optical disc.
These include CDs, DVDs, and Blu-ray discs. This allows you to play music or watch movies
using pre-recorded discs. Computer software also often comes on one of these discs, so you need
an optical drive to install software. Most modern drives allow you to write to an empty disc, so
you can create your own music CDs or create a back-up copy of important data.

An optical disk drive uses a laser to read and write data. A laser in this context means an
electromagnetic wave with a very specific wavelength within or near the visible light spectrum.
Different types of discs require different wavelengths. For compact discs, or CDs, a wavelength
of 780 nanometers (nm) is used, which is in the infrared range. For digital video discs, or DVDs,
a wavelength of 650 nm (red) is used, while for Blu-ray discs, a wavelength of 405 nm (violet) is
used.
An optical drive that can work with multiple types of discs will therefore contain multiple lasers.
The mechanism to read and write data consists of a laser, a lens to guide the laser beam, and
photodiodes to detect the light reflection from the disc.
The optical mechanism for reading CDs and DVDs are quite similar, so the same lens can be
used for both types of discs. The mechanism for reading Blu-ray discs, however, is quite
different. An optical drive that works with all types of discs will therefore have two separate
lenses: one for CD/DVD and one for Blu-ray.
An optical disc drive with separate lenses for CD/DVD and for Blu-ray discs
optical drive lenses
In addition to the lens, an optical drive has a rotational mechanism to spin the disc. Optical
drives were originally designed to work at a constant linear velocity (CLV) - this means that the
disc spins at varying speeds depending on where the laser beam is reading, so the spiral groove
of the disc passes by the laser at a constant speed. This means that a disc spins at around 200
rotations per minute (rpm) when the laser is reading near the outer rim of the disc and at around
500 rpm when reading near the inner rim.
This constant speed is very important for music CDs and movie discs, since you want to listen to
music or watch a movie at the regular speed. For other applications, however, such as reading or
writing other types of data, working at this speed is not needed. Modern optical drives can often
spin much faster, which results in higher transfer speeds. When you see an optical drive reported
as a 4x drive, for example, this means it can spin at four times the base-speed (i.e., between 800
and 2,000 rpm).
An optical drive also needs a loading mechanism. Two general types are in use:
A tray-loading mechanism, where the disc is placed onto a motorized tray, which moves in and
out of the computer case.
A slot-loading mechanism, where the disc is slid into a slot and motorized rollers are used to
move the disc in and out.
Tray-loading mechanisms for optical drives in desktop computers tend to be rather bulky.
Typical tray-loading optical drive for desktop computers

optical disk drive for desktop
For laptops, the tray-loading mechanism is much smaller.
Q-4: Describe different types of ROM?
Types of ROM: ROM is divided into following types:
1) PROM
2) EPROM
3) EEPROM
1- PROM: PROM stands for Programmable Read Only Memory. This form of ROM is initially
blank. The user or manufacturer can write data/program on it by using special devices. However,
once the program or data is written in PROM chip, it cannot be changed. If there is an error in
writing instructions or data in PROM, the error cannot be erased. PROM chip becomes unusable.
2- EPROM: EPROM stands for Erasable Programmable Read Only Memory. This form of
ROM is also initially blank. The user or manufacturer can write program or data on it by using
special devices. Unlike PROM, the data written in EPROM chip can be erased by using special
devices and ultraviolet rays. So program or data written in EPROM chip can be changed and new
data can also be added. When EPROM is in use, its contents can only be read.
3- EEPROM: EEPROM stands for Electrically Erasable Programmable Read Only Memory.
This kind of ROM can be written or changed with the help of electrical devices. So data stored in
this type of ROM chip can be easily modified.
Q-5: Write down the application of ROM?
There are four types of ROM: regular ROM, PROM, EPROM and EAROM.
ROM stands for read only memory. A ROM can’t be changed, which means that once it has been
manufcatured the contents of it can’t be changed.
The fact thaht ROMs are permanent gives them a security over programs stored in regular
memory which can be changed by powerloss, viruses,
hackers and accidental misstakes. A typical application of a ROM might be an industrial
machine that reapets the same sequence over and over
to manufcature auto parts. Another example might be the boot up software for a regular PC,
which performs the same task each time the power is turned on.
ROMs however also have som disadvantages. One is that it takes a long time to manufacture a
rom, which means that you might loose revenues due to cost delays. Abnother one is that the unit
price of a ROM is quite high which means that you have to order at least something like

thousand units, this fact makes the intial investment cost high. Once the ROM has been
manfactured and in error has been discovered in the information store you can’t change the
contents, this means making misstakes are very expensive.
To solve the problems of rom three other types of user programmable ROMs has been
developed: PROM, EPROM and EAROM.
PROM stands for Programmable ROM. Information is program into a prom by burning of
different electrical connection points. Depending of what’s is burned you code either ao one or a
zero into the rom. PROMs are relatively cheap to manfucaturer which means that misstakes are
not as expensive. PROMs are often used for testing phases where
you need to try out many different programs before finding the right one. When the right
program has been found an eletrically compatbile ROM can take the place of PROM giving the
final product a greater relability. However if you need to make frequent changes you have to
discared one PROM each time which will be a vaste of money in the long run. Therefore there
are ROMs which can be erased and reprogrammed by the user.
EPROM stands from electrically programmable ROM. You can erasure the contents of a an
EPROM by submitting it to ultraviolet let for five to ten minutes. The circuits are however
relatively expensive per unit and aren’t pin compatbile with PROMS and ROMS, this means that
you have to change a design of the circuit board when you wish to make the final product which
often uses ROMs. EPROMs loose their charge of many years pass by which means that if you
have applications which will run for many years you should choose ROMs or PROMs instead.
Finally there are EAROM which stands for Electrically alterabkle ROM. These ROMS can be
both written and read. However writing is very slow so it can be considered as a read often
memory. EARoms is an expensive and complex technolog and is therefore most oftenly used for
industrial and military applications.
To sum it up the kind of ROM you will use depends on the application type.
Q-6: Memory related Math

Chapter-6
Networking
Q-1: As a Manager you want to use computer network in your organization, What may be
the possible reasons of using computer network?
Your business has more than one computer, chances are you could benefit from networking
them. A local area network (LAN) connects your company’s computers, allowing them to share
and exchange a variety of information. While one computer can be useful on its own, several
networked computers can be much more useful.
Here are some of the ways a computer network can help your business:
File sharing: Have you ever needed to access a file stored on another computer? A network
makes it easy for everyone to access the same file and prevents people from accidentally creating
different versions.
Printer sharing: If you use a computer, chances are you also use a printer. With a network,
several computers can share the same printer. Although you might need a more expensive printer
to handle the added workload, it’s still cheaper to use a network printer than to connect a
separate printer to every computer in your office.
Communication and collaboration: It’s hard for people to work together if no one knows what
anyone else is doing. A network allows employees to share files, view other people’s work, and
exchange ideas more efficiently. In a larger office, you can use e-mail and instant messaging
tools to communicate quickly and to store messages for future reference.
Organization: A variety of scheduling software is available that makes it possible to arrange
meetings without constantly checking everyone’s schedules. This software usually includes other
helpful features, such as shared address books and to-do lists.
Remote access: Having your own network allows greater mobility while maintaining the same
level of productivity. With remote access in place, users are able to access the same files, data,
and messages even when they’re not in the office. This access can even be given to mobile
handheld devices.
Data protection: You should know by now that it’s vital to back up your computer data
regularly. A network makes it easier to back up all of your company’s data on an offsite server, a
set of tapes, CDs, or other backup systems. (Of course, another aspect of data protection is data
security

Q-2: Briefly describe the classification of computer network?
There are several different types of computer networks. Computer networks can be characterized
by their size as well as their purpose.
The size of a network can be expressed by the geographic area they occupy and the number of
computers that are part of the network. Networks can cover anything from a handful of devices
within a single room to millions of devices spread across the entire globe.
Some of the different networks based on size are:
 Personal area network, or PAN
 Local area network, or LAN
 Metropolitan area network, or MAN
 Wide area network, or WAN
Personal Area Network: A personal area network, or PAN, is a computer network organized
around an individual person within a single building. This could be inside a small office or
residence. A typical PAN would include one or more computers, telephones, peripheral devices,
video game consoles and other personal entertainment devices.
If multiple individuals use the same network within a residence, the network is sometimes
referred to as a home area network, or HAN. In a very typical setup, a residence will have a
single wired Internet connection connected to a modem. This modem then provides both wired
and wireless connections for multiple devices. The network is typically managed from a single
computer but can be accessed from any device.
This type of network provides great flexibility. For example, it allows you to:
Send a document to the printer in the office upstairs while you are sitting on the couch with your
laptop.
Upload the photo from your cell phone to your desktop computer.
Watch movies from an online streaming service to your TV.
If this sounds familiar to you, you likely have a PAN in your house without having called it by
its name.
Local Area Network: A local area network, or LAN, consists of a computer network at a single
site, typically an individual office building. A LAN is very useful for sharing resources, such as
data storage and printers. LANs can be built with relatively inexpensive hardware, such as hubs,
network adapters and Ethernet cables.

The smallest LAN may only use two computers, while larger LANs can accommodate thousands
of computers. A LAN typically relies mostly on wired connections for increased speed and
security, but wireless connections can also be part of a LAN. High speed and relatively low cost
are the defining characteristics of LANs.
LANs are typically used for single sites where people need to share resources among themselves
but not with the rest of the outside world. Think of an office building where everybody should be
able to access files on a central server or be able to print a document to one or more central
printers. Those tasks should be easy for everybody working in the same office, but you would
not want somebody just walking outside to be able to send a document to the printer from their
cell phone! If a local area network, or LAN, is entirely wireless, it is referred to as a wireless
local area network, or WLAN.
Metropolitan Area Network: A metropolitan area network, or MAN, consists of a computer
network across an entire city, college campus or small region. A MAN is larger than a LAN,
which is typically limited to a single building or site. Depending on the configuration, this type
of network can cover an area from several miles to tens of miles. A MAN is often used to
connect several LANs together to form a bigger network. When this type of network is
specifically designed for a college campus, it is sometimes referred to as a campus area network,
or CAN.
Wide Area Network: A wide area network, or WAN, occupies a very large area, such as an
entire country or the entire world. A WAN can contain multiple smaller networks, such as LANs
or MANs. The Internet is the best-known example of a public WAN
Q-3: Define Internet, Intranet and Extranet.
Internet: A means of connecting a computer to any other computer anywhere in the world via
dedicated routers and servers. When two computers are connected over the Internet, they can
send and receive all kinds of information such as text, graphics, voice, video, and computer
programs.
No one owns Internet, although several organizations the world over collaborate in its
functioning and development. The high-speed, fiber-optic cables (called backbones) through
which the bulk of the Internet data travels are owned by telephone companies in their respective
countries.
Intranet: Intranet a network that works like the Internet but can only be used by certain people
(such as the employees of a company). This is a network that is not available to the world outside
of the Intranet. If the Intranet network is connected to the Internet, the Intranet will reside behind
a firewall and, if it allows access from the Internet, will be an Extranet. The firewall helps to
control access between the Intranet and Internet to permit access to the Intranet only to people
who are members of the same company or organisation.

Extranet: An Extranet is actually an Intranet that is partially accessible to authorised outsiders.
The actual server (the computer that serves up the web pages) will reside behind a firewall. The
firewall helps to control access between the Intranet and Internet permitting access to the Intranet
only to people who are suitably authorised. The level of access can be set to different levels for
individuals or groups of outside users. The access can be based on a username and password or
an IP address (a unique set of numbers such as 209.33.27.100 that defines the computer that the
user is on).
Q-4: What is protocol? What are the functions of protocol?
Protocol: A protocol is the special set of rules that end points in a telecommunication connection
use when they communicate. Protocols specify interactions between the communicating entities.
When you send or receive data (for example, an e-mail note or a Web page), the message gets
divided into little chunks called packets. Each of these packets contains both the sender's Internet
address and the receiver's address. Any packet is sent first to a gateway computer that
understands a small part of the Internet. The gateway computer reads the destination address and
forwards the packet to an adjacent gateway that in turn reads the destination address and so forth
across the Internet until one gateway recognizes the packet as belonging to a computer within its
immediate neighborhood or domain. That gateway then forwards the packet directly to the
computer whose address is specified.
Because a message is divided into a number of packets, each packet can, if necessary, be sent by
a different route across the Internet. Packets can arrive in a different order than the order they
were sent in. The Internet Protocol just delivers them. It's up to another protocol, the
Transmission Control Protocol (TCP) to put them back in the right order.
IP is a connectionless protocol, which means that there is no continuing connection between the
end points that are communicating. Each packet that travels through the Internet is treated as an
independent unit of data without any relation to any other unit of data. (The reason the packets
do get put in the right order is because of TCP, the connection-oriented protocol that keeps track
of the packet sequence in a message.) In the Open Systems Interconnection (OSI)
communication model, IP is in layer 3, the Networking Layer.
The most widely used version of IP today is Internet Protocol Version 4 (IPv4). However, IP
Version 6 (IPv6) is also beginning to be supported. IPv6 provides for much longer addresses and
therefore for the possibility of many more Internet users. IPv6 includes the capabilities of IPv4
and any server that can support IPv6 packets can also support IPv4 packets.
Q-5: What are the differences between synchronous and asynchronous data transmission?
With asynchronous transmission signal timing is not required; signals are sent in an agreed
pattern of bits and if both ends are agreed on the pattern then communication can take place.

Bits are grouped together and consist of both data and control bits. If the signal is not
synchronised the receiver will not be able to distinguish when the next group of bits will arrive.
To overcome this the data is preceded by a start bit, usually binary 0, the byte is then sent and a
stop bit or bits are added to the end. Each byte to be sent now incorporates extra control data. In
addition to the control data small gaps are inserted between each chunk to distinguish each
group.
In asynchronous transmission each bit remains timed in the usual way. Therefore, at bit level the
transmission is still synchronous (timed). However, the asynchronous transmission is applied at
byte level, once the receiver realises that there is a chunk of incoming data timing
(synchronisation) takes place for the chunk of data.
Asynchronous transmission is relatively slow due to the increased number of bits and gaps. It is a
cheap and effective form of serial transmission and is particularly suited for low speed
connections such as keyboard and mouse.
One example of asynchronous transfer is Asynchronous Transfer Mode (ATM) switching. ATM
allows voice, data and video to be transmitted in fixed length cells of 53 bytes.
Q-6: What do you mean by VOIP? What are the functions of VOIP?
VoIP (voice over IP) is an IP telephony term for a set of facilities used to manage the delivery of
voice information over the Internet.VoIP involves sending voice information in digital form in
discrete packets rather than by using the traditional circuit-committed protocols of the public
switched telephone network (PSTN). A major advantage of VoIP and Internet telephony is that it
avoids the tolls charged by ordinary telephone service.
Despite VoIP based phones having numerous functions, in practice a user does not know them or
forgets them. Below we discuss 6 functions of IP telephones which, given support from the
operator’s platform, make the daily grind of every workplace that much easier.
Busy Lamp Field (BLF): BLF is a function ever more often decisive in the choice of a given IP
telephone model. However, many users identify it solely with diodes flashing to signal an active
connection, reminiscent of the old systemic telephones. However, that is not all. Apart from
signalling that a line is busy by a flashing diode, it also allows one to preview the telephone
number from which a call is being made to a given line. That is why the Visual alert for BLF
makes it possible to decide whether such a call requires immediate capturing or if it can wait.
‘Follow me’ function
Many VoiP users are surprised by the possibility to use this to of solution. A simple and yet a
very useful function to divert a call, which, from one number, will be directed to 2 telephones at
the same time – a landline and a mobile number, or first the landline and then mobile. Thus it is

possible to take the call on a device, which will be convenient for us at the given time, without
worries that upon leaving the office we will miss important telephone calls.
A number of phones with the same telephone number
Lets imagine a situation where we have to be available on our office number but at the same time
our job requires us to move around the office (often the case in IT departments). This simple
solutions comes to the rescue, or 2 telephones with the same number, e.g. we are using a desk
based telephone and a DECT or WiFi handset.
‘Call parking’ function
The next unappreciated but useful function is call parking, which literally does as its name
dictates. It entails an option to put the current call on hold on one phone and continue it from
another. Particularly helpful if we have to change rooms.
DND – “do not disturb” mode
How many times have you had a situation where you had to chase to meet a deadline but the
telephone did not stop ringing? Through DND (do not disturb), or a function which shows a busy
line, you are able to complete your task in peace and quiet, without being distracted by incoming
calls.
Remote account registration
Are you on a business trip? There is nothing stopping you from calling and taking calls on your
company number. Through IP-PBX exchanges you are able to use your telephone number not
only at the office, but from any locations with Internet access. All you need is a telephone (WiFi
for example) or a smartphone with softphone installed.
The above functions are only a select few from the pool of useful solutions which are at our
fingertips when we implement VoIP telephony at our business. Please ask your installer
regarding additional possibilities, which will save our time and add flexibility.
Q-7: What do you mean by http, SMTP, FTP, POP, URL, DNS?
The Hypertext Transfer Protocol (HTTP) is an application protocol for distributed, collaborative,
hypermedia information systems. HTTP is the foundation of data communication for the World
Wide Web. Hypertext is structured text that uses logical links (hyperlinks) between nodes
containing text.
File Transfer Protocol (FTP) lives up to its name and provides a method for copying files over a
network from one computer to another. More generally, it provides for some simple file

management on the contents of a remote computer. It is an old protocol and is used less than it
was before the World Wide Web came along. Today, Its primary use is uploading files to a Web
site. It can also be used for downloading from the Web but, more often than not, downloading is
done via HTTP. Sites that have a lot of downloading (software sites, for example) will often have
an FTP server to handle the traffic. If FTP is involved, the URL will have ftp: at the front.
Email requires its own set of protocols and there are a variety, both for sending and for receiving
mail. The most common protocol for sending mail is Simple Mail Transfer Protocol (SMTP).
When configuring email clients, an Internet address for an SMTP server must be entered. The
most common protocol used by PCs for receiving mail is Post Office Protocol(POP). It is now in
version 3 so it is called POP3. Email clients require an address for a POP3 server before they can
read mail. The SMTP and POP3 servers may or may not be the same address. Both SMTP and
POP3 use TCP for managing the transmission and delivery of mail across the Internet.
The Hypertext Transfer Protocol (HTTP) is an application protocol for distributed, collaborative,
hypermedia information systems. HTTP is the foundation of data communication for the World
Wide Web. Hypertext is structured text that uses logical links (hyperlinks) between nodes
containing text.
URL is an acronym for Uniform Resource Locator and is a reference (an address) to a resource
on the Internet. A URL has two main components: Protocol identifier: For the URL
http://example.com , the protocol identifier is http . Resource name: For the URL
http://example.com , the resource name is example.com.
DNS is an abbreviation for Domain Name System, a system for naming computers and network
services that is organized into a hierarchy of domains. DNS naming is used in TCP/IP networks,
such as the Internet, to locate computers and services through user-friendly names.
Chapter-7
Database
Q-1: Define field file record and database?
A File: A database file is a mass of random information, or resource for storing information,
which is available to a computer program and is usually based on some kind of long-lasting
storage. A file is long-lasting in the sense that it remains available for programs to use after the
current program has finished.
A Record: In database management systems a record is a complete set of information. Records
are composed of fields, each of which contains one item of information. A set of records makes

up a file. For example, a personnel file might contain records that have three fields: a name field,
an address field, and a phone number field.
field file record: A database field is a space chosen for a particular item of information. A tax
form, for example, contains a number of fields:
 one for your name,
 one for your Social Security number,
 one for your income, and so on.
Database: A database is a collection of information that is organized so that it can easily be
accessed, managed, and updated. In one view, databases can be classified according to types of
content: bibliographic, full-text, numeric, and images.
Q-2: What is primary key?
A primary key, also called a primary keyword, is a key in a relational database that is unique for
each record. It is a unique identifier, such as a driver license number, telephone number
(including area code), or vehicle identification number (VIN).
Q-3: What is query language? What are the function of query language?
Query language is a set of commands used in retrieving data from (or modifying or updating) a
database. See also structured query language.
Q-4: What are the advantages and disadvantages of database system?
Advantages and Disadvantages of DBMS:
In the article problems with the traditional File Processing System, you have seen the different
problems with the existing traditional File Processing system. So, to overcome those problems,
the Database Management System was Introduced.
"A database management system (DBMS) is a collection of programs that manages the database
structure and controls access to the data stored in the database".
The DBMS serves as the intermediary between the user and the database. The database structure
itself is stored as a collection of files, So, we can access the data in those files through the
DBMS. The DBMS receives all application requests and translates them into the complex
operations required to fulfill those requests. The DBMS hides much of the database’s internal
complexity from the application programs and users.

The Different Advantages of DBMS
1. Improved data sharing
The DBMS helps create an environment in which end users have better access to more and
better-managed data. Such access makes it possible for end users to respond quickly to changes
in their environment.
2. Improved data security
The more users access the data, the greater the risks of data security breaches. Corporations
invest considerable amounts of time, effort, and money to ensure that corporate data are used
properly. A DBMS provides a framework for better enforcement of data privacy and security
policies.
3. Better data integration
Wider access to well-managed data promotes an integrated view of the organization’s operations
and a clearer view of the big picture. It becomes much easier to see how actions in one segment
of the company affect other segments.
4. Minimized data inconsistency
Data inconsistency exists when different versions of the same data appear in different places. For
example, data inconsistency exists when a company’s sales department stores a sales
representative’s name as “Bill Brown” and the company’s personnel department stores that same
person’s name as “William G. Brown,” or when the company’s regional sales office shows the
price of a product as $45.95 and its national sales office shows the same product’s price as
$43.95. The probability of data inconsistency is greatly reduced in a properly designed database.
5. Improved data access
The DBMS makes it possible to produce quick answers to ad hoc queries. From a database
perspective, a query is a specific request issued to the DBMS for data manipulation—for
example, to read or update the data. Simply put, a query is a question, and an ad hoc query is a
spur-of-the-moment question. The DBMS sends back an answer (called the query result set) to
the application. For example, end users, when dealing with large amounts of sales data, might
want quick answers to questions (ad hoc queries) such as:
- What was the dollar volume of sales by product during the past six months?
- What is the sales bonus figure for each of our salespeople during the past three months?
- How many of our customers have credit balances of 3,000 or more?

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