this pptx is short introduction of computer an its applications

1. 1

2. Chapter 1
Introduction to Computers

3. Contents
 What is Computer?
 Types of Computers
 Categories of Computers
 Uses of Computer
 Computers in Near Future

4. What is Computer?
Chapter 1 - Introduction to Computer

5. What is Computer?
 “Computer” derived from “compute”  means to calculate
 In past, computer was normally considered to be a calculating de
used to perform arithmetic operations
 But today, computers are used in every field of life to solve problem
different kinds
 Definition of Computer
– A computer is an electronic machine that is used to solve different kinds of
problems according to a set of instructions given to it
 Function of computer
– Accepts data and instructions (as input) and stores them in its own memory
– Processes or manipulates data according to given instructions and prod
information (known as output)
– Stores information permanently on storage devices for later use

6. What is Computer?
 Computer consists of many electric, electronic, and mechanical components
 components known as hardware
 A computer performs different operations under the control of instructions
– These instructions tell the computer how to perform a particular task
– Some instructions also control the operations of different components of computer
 A set of instructions that can be given to a computer to perform a particula
task or to control different operations of computer  computer software o
computer program
– A computer cannot perform any task without software
 A combination of hardware and software  computer system
 Small computers are also fitted (embedded) into many other electronic
devices  mobile phones, toys, microwave ovens, vehicles, and MP3

7. Data & Information
Data
 Word ‘data’ refers to facts concerning things, people, objects, events, etc.
 A collection of raw facts and figures  data
 Word ‘raw’ means unprepared or unprocessed
 Data may consist of text, numbers, images, audio, and video
 Data is collected for different purposes
 It does not give clear and proper meanings
– It cannot be used directly for decision-making
 Example  A list of class students, showing students roll numbers, names,
obtained marks, etc.
Information
 Processed data
 Processed data (information) gives clear and proper meanings
– It can be used for decision-making

8. Data Processing
 A process to convert data into information
 Different operations are performed on data to convert it into useful
information
– Operations  arithmetic, data sorting, and data formatting
 Data can be processed manually or by using a computer
 Today, data is processed using a computer
 Data and instructions are given to computer, It processes data
according to given instructions and converts into required information
or results

9. Information Technology
 Technology used for processing, storing, and communicating information
– Technology  Easiest way of working using some technique and machine
 Combination of telecommunication technology and computer technology
(hardware and software)
 It combines computing with high-speed communication links for carrying
data from one place to another, all over the world
 Website is a type of information technology
 Major components of information technology
– Data or information
– Medium or communication network
– Computer hardware and software
 World has become a global village due to IT
– Global village  people living in the world know each other as if they are living in a
village
 People can exchange information or messages in such a manner as if they
are sitting in a drawing-room, face to face

10. Characteristics of Computer
Speed
 High-speed electronic device
 A computer can perform billions or trillions of operations or tasks per second
– Operations  arithmetic & sorting operations, displaying images, recording audio/video,
playing music, and showing video or movie
 Speed of a computer  in microseconds or nanoseconds
 Usually, measured in Mega Hertz (MHz) or Giga Hertz (GHz)
 Different computers have different speeds
Accuracy
 Computer does not make any kind of mistakes in calculations
 It processes data and produces a 100% accurate result
 Accuracy of result depends upon correct input data and set of instructions given to
computer
– If any mistake in input data  computer does not produce an accurate result
 Computer can perform billions or trillions of operations in one second without any
error

11. Characteristics of Computer
Reliability
 Electronic components in a modern computer have a very low failure rate
 Modern computer can perform complicated calculations without creating any problem
 In general, computers are very reliable and do all tasks accurately
 Many personal computers have never needed a service call
 Communication networks are also very reliable and generally available whenever needed
 Nowadays, all large industries and organizations/companies are dependent on compute
and their entire business is running through computers  have blindly trust in computers
Consistency
 People often have difficulty to repeat the same actions again and again in same way an
to get the same result
– For example, a lecturer feels difficulty to repeat a lecture in a classroom again and again
 A computer can repeat same actions consistently (again and again) without losing
concentration
– To run a spell checker (built into a word processor) for checking spelling in a document
– To play multimedia animation for training purposes
– To deliver a lecture through a computer in a classroom etc.
 A computer will carry out the activity in an exact manner every time

12. Characteristics of Computer
Memory / Storage
 A computer has internal memory (storage)  primary memory
– Computer stores instructions of the program and data in primary memory during data processing
– Temporary memory
– Data and programs can be stored in it as long as computer is processing data
– When a computer is turned off, everything from primary memory is erased
 A computer also has external storage  secondary storage
– A large amount of data and programs can be stored permanently
– Stored data or information is available anytime
– Examples  hard disk, USB drive, and CD
Automation
 Once data and instructions are given to the computer; it can automatically perform
different operations on data
 A computer can also control automatically different devices attached to it
 It executes automatically program instructions one by one without any human
assistance

13. Characteristics of Computer
Versatility
 Versatility refers to capability of a computer to perform different kinds of
tasks with same accuracy & efficiency
 Different types of tasks can be performed through computer
– At one moment we are playing a game on computer, the next moment we are
composing and sending an e-mail, etc.
– In colleges and universities, computers are used to deliver lectures to students
 That is why computers are being used in every field of life such as
universities/colleges, hospitals, banks, offices, hotels, at homes, industries
for manufacturing products, etc.
Multitasking
 A computer has the capability of multitasking
 A user can perform multiple tasks on computer at the same time
 Example  a user can print a document on printer, while listening to naats.

14. Characteristics of Computer
Communication
 A computer has capability of communicating with other computers in a computer network
 Nowadays, computers are mostly used for exchanging messages or information through
computer networks all over the world
– Example  information can be received or sent through Internet with the help of computers
Diligence
 A computer can continuously work for hours without creating any error
 It does not get tired while working
 After hours of work, it performs operations with same accuracy and speed as first one
No Feelings
 A computer has no feelings or emotions
 It detects objects based on the instructions given to it
 Based on our feelings, taste, knowledge, and experience we can make certain decisions
and judgments in our daily life
 On the other hand, a computer cannot make such judgments on its own
 Its judgments are totally based on the instructions given to it

15. Disadvantages of using Computers
 Health Risks
 Data Security Problems
 Wastage of Time
 Computer Viruses
 Unemployment
 Privacy Violation
 Computer Crimes
Details are given in book on each point

16. Types of Computers
Chapter 1 - Introduction to Computer

17. Analog Computers
 Word “analog” means continuously varying in quantity
 Analog computers accept input data in continuous form and output is
obtained in the form of graphs
 These computers accept input and give output in the form of analog signals
 Output is measured on a scale
 Examples of analog data  voltage, current, sound, speed, temperature,
pressure, etc. values
– These values continuously increase and decrease
 Analog computers are used to measure continuous values
 Analog computers are usually built for special purposes
 They have very high-speed computing elements used to process physical
quantities
 Analog computers have low memory size and have fewer functions

18. Analog Computers
 Early special-purpose analog computing devices were Slide Rule,
Curvimeter & Plainmeter, and the Harmonic Analyzer
 In World War II, analog computing mechanism was of great importance
for gunfire control on warships
 Analog computers are used in industrial units to control various
processes
 They are also used in different fields of engineering and medicine
 General-purpose analog computer was first manufactured in 1930s
Examples of Analog Devices
– Thermometer  used to measure temperature
– Analog Clock  measures time by means of distance continuously covered by
needle around a dial
– Voltmeter  used to measure voltage
– Speedometer  used to measure speed of a car

19. Digital Computers
 Word “digital” means discrete
 It refers to a binary system, which consists of only two digits, i.e. 0 and 1
 Digital data consists of binary data represented by OFF (low) and ON (high)
electrical pulses
 These pulses are increased and decreased in discontinuous form rather
than in continuous form
 In digital computers, quantities are counted rather than measured
 A digital computer operates by counting numbers or digits and gives output
in digital form
 It represents data in digital signals 0 and 1 and then processes it using
arithmetic and logical operations
 Today most of the computers used in business, educational institutions,
hospitals, offices, and at homes are digital computers
– Examples  IBM PC and Apple Macintosh
– Calculators, digital watches, digital scoreboards, and digital thermometers

20. Hybrid Computers
 Combined features of both analog and digital computers
 These computers contain both digital and analog components
 In hybrid computers, users can process both continuous (analog) and
discrete (digital) data
 These are special-purpose computers
 These are very fast and accurate
 These are used in scientific fields
 In hospitals, these are used to watch the patient’s health condition in
ICU (Intensive Care Unit)
 These are also used in telemetry, spaceships, missiles, etc.

21. Categories of Computers
Chapter 1 - Introduction to Computer

22. Categories of Computers
 Computers are being manufactured in different sizes, data processing speeds, etc.
 Computers are classified according to their data processing speed, amount of data
that they can hold, and price
 Generally, a computer with high processing speed and large internal storage is
called a big computer
 Due to rapidly improving technology, however, distinction among categories of
computers is not always clear-cut
 Today many mobile phones (cell phones) are available that also have many
computing features
– For example, they have a media player and web browsing capabilities
 Depending upon the computer’s size, speed, memory size, and price, computers
are classified into the following categories:
– Supercomputers
– Mainframe Computers
– Minicomputers

23. Supercomputer
 Most powerful and fastest computer
 It can process huge amounts of data and can solve complicated problems
 It can perform more than one trillion calculations per second
 A modern supercomputer consists of thousands of processors that work
parallel to complete a specific task
– Task is divided into parts and these parts of the task are performed on different
processors at the same time
– So parallel processing is done in a supercomputer
 In a single supercomputer, thousands of users can be connected at same
time
 Supercomputer handles work of each user separately
 Most expensive  cost is up to several billion dollars
 Example  Deep Blue (developed by IBM)

24. Supercomputer
 Purpose of Supercomputers in
– Weather forecasting
– Nuclear energy research
– Aircraft design
– Automotive design
– Weapon design
– Controlling industrial units
– Oil and gas exploration
 Supercomputers are used in large organizations, research laboratories,
aerospace centers, large industrial units, etc.
 Nuclear scientists use supercomputers to create and analyze models of
nuclear fission and fusions
 In Pakistan, supercomputers are used in many organizations, like Atomic
Energy Research Centre and Missile Control Systems

25. Mainframe Computers
 Second powerful computer
 Physically large sized computer that covers about 1000 sq feet
 Expensive
 Consists of multiple processors
 It can process trillions of instructions per second (TIPS)
 Largest mainframe computer can handle thousands of connected users
simultaneously
 It fulfills requirements of all the users and controls their operations
 Users often access the mainframe computer by a device  terminal
 Types of terminals  dumb terminals & intelligent terminals
– Dumb terminal  is simply an input/output (I/O) device. It has no processing and storage
capabilities. Usually, it consists of a keyboard and display screen or touch screen.
– Intelligent terminal  can perform some processing operations, but it usually does not have
any storage.
– Intelligent terminals are faster than dumb terminals
 In some mainframe environments, however, users can use a standard personal
computer to access the mainframe computer

26. Mainframe Computers
 Mainframe computers are used in large organizations such as
insurance companies, banks, and government departments, where
many people frequently need to use or access the same data
 Mainframe computers are also specially used as servers in a network
environment
 Example  IBM S/390

27. Minicomputers
 This category of computer is named as minicomputer because of their small size
as compared to other computers at that time
 Capabilities of a minicomputer are less than a mainframe computer but more than
a personal computer
 Also known as midrange computer
 First minicomputer was introduced in the mid–1960s
 Like a mainframe computer and supercomputer, a minicomputer also consists of
multiple processors
 Largest minicomputer can handle hundreds of users simultaneously
 Users can access minicomputer through terminals or standard personal computers
 Minicomputers are used in small businesses, education, scientific research, and
many other government departments
 Although some minicomputers are designed for a single user but most are
designed to handle multiple users
 A minicomputer can also be used as a server in a network environment
 Example  IBM AS/400

28. Personal Computers
 Personal computers (or simply PCs)  also called microcomputers
 Personal computers are typically developed for individual users
 It can be used by only one person at a time
 Today most PCs can communicate with other computers and devices
 A personal computer contains a processor (microprocessor), memory, input/output
devices, and storage devices
 It also contains communication devices
 Personal computers are very small in size and less expensive
 They are commonly used in almost every field of life such as at homes, small offices,
education, etc.
 They are available in different sizes and shapes
 IBM company designed first personal computer in 1981  named IBM-PC
 After this, many computer hardware companies copied the design of IBM-PC
 Most popular architectures of personal computers  PC and Apple
 Term “PC-compatible” refers to any personal computer based on the original IBM personal
computer design
– PC and PC-compatible computers use the Windows operating system

29. Personal Computers
Desktop Computers
 Most common type of personal computer
 All components of this computer can easily fit on a desk or table
 Main component of desktop PC is system unit
 System unit of a desktop PC can lie flat on or under a desk or table
 Desktop computers are available in different models
 In one model, system unit is placed horizontally on the desktop or table
and monitor is usually placed on system unit
 In another model, known as a tower model, both system unit and
monitor are placed on desk or table separately (system unit is placed
vertically)

30. Personal Computers
Portable Computers
 Types of PCs that can easily be carried from place to place  portable computers or mob
computers
 These computers run on rechargeable batteries, power supply, or both
Laptops
 Also called a notebook computer
 Small size (85-by-11 inch notebook) computer and can fit inside a briefcase
 Lightweight and its weight is about 4 pounds (1.8 Kg)
 Uses less electric power than a desktop computer
– Most laptops can operate on a rechargeable battery
 Especially in the education field, a laptop has become the need of every student and teacher
 A laptop is more expensive than a desktop computer
 We can use a laptop by placing it on our lap  That is why named as a laptop
 A laptop computer can perform the same functions as a desktop computer
 A laptop also has same input/output and storage devices as a desktop computer
– However, a laptop has a built-in keyboard with a trackball or touchpad
– Keyboard is fitted on the top of system unit
– Usually uses LCD (Liquid Crystal Display) monitor to display information
– Monitor is attached to system unit with hinges

31. Personal Computers
Portable Computers
Tablets
 A tablet is like a laptop and can perform the same functions as a laptop
 Physically smaller than a laptop and larger than a mobile phone
 It has a touch screen that is used for both input and output
 Usually, a digital pen or stylus as an input device is used for entering
data and selecting different options or objects on the screen
 A standard keyboard can also be attached to a tablet for entering data
 A tablet also supports voice input
 Many tablets have a built-in microphone and special software that
accepts input from the user’s voice
 Like a laptop, a tablet is usually run on a rechargeable battery

32. Personal Computers
Portable Computers
Tablets
 Types of Tablet
 Slate Tablet
– This type of tablet does not contain a physical keyboard
– It uses an on-screen virtual keyboard for input
– A physical keyboard can also be attached to this type of tablet
 Convertible Tablet
– This type of tablet has a display screen that is attached to a keyboard
– Display screen can be rotated at 180 degrees and can be folded down over
keyboard

33. Mobile Devices
 Small computing devices that can fit in the hand (or in a pocket)
 These devices have small screens and some of them have small
physical keyboards
 These devices store information and programs permanently on special
storage media  memory cards (or smart cards)
 A mobile device can be connected to personal computer for
exchanging data
 Today, most of the mobile devices are Internet-enabled
– It means that they can be connected to Internet wirelessly for accessing
information on the Internet
 Most of the mobile devices are operated by a rechargeable battery
 Most popular types of mobile devices  smartphones, handheld
computers, PDAs, portable media players, and e-book readers

34. Mobile Devices
Smartphones
 Today, smartphones/mobile phones are commonly used for communications
between people
 A smartphone is an Internet-enabled phone
 It provides the functions to receive & send e-mails and to access Whatsapp,
Facebook, etc. through Internet
 Most of the smartphones have touch screens for dialing phone numbers and
for entering information
 Smartphones can communicate wirelessly with other devices or computers
 Similarly, many smartphones can function as a media player
 They include built-in digital cameras so that users can share videos or
photos
 They also offer a variety of other application software such as word
processing, spreadsheet, games, and the capability of conducting live video
conferences

35. Mobile Devices
Handheld Computers
 In the mid-1990s, many new types of small computing devices have
been introduced  known as handheld computers
 A handheld computer can fit in the hand  that is why called handheld
computer
 In this computer, a digital pen or stylus is usually used as an input
device
 Some handheld computers have a specialized small keyboard
 Many handheld computers can communicate wirelessly with other
computing devices or computers
 Handheld computers are also used by mobile employees  meter
readers & parcel delivery people

36. Mobile Devices
PDAs
 PDA stands for Personal Digital Assistant
 PDA is one of the more popular lightweight mobile devices in use today
 Many PDAs are web-based and users can send/receive e-mails and
access Internet
 Similarly, some PDAs also provide telephone capabilities
 Primary input device of a PDA  stylus
– A stylus is an electronic pen and looks like a small ballpoint pen
 Some PDAs have a small built-in keyboard
 Some PDAs also support voice input
 They also have built-in cameras and can function as a portable media
player

37. Mobile Devices
Portable Media Players
 Electronic mobile device
 It is used to listen to music, watch videos, movies, and television
shows
 It also provides the facility to organize pictures, music, and videos
 Some portable media players are Internet-enabled
– It means that users can access the Internet and send /receive e-mail messages
 Some offer a variety of other application software  word processing,
spreadsheet, games, and other application software
 Some portable media players have a touch screen, while others have a
touch-sensitive pad
 Touch screen or touchpad is used to navigate through images/videos,
adjust volume, and other settings

38. Mobile Devices
E-Book Readers
 An e-book reader (electronic book reader)  also called an
e-reader
 It is a mobile device that is used for reading e-books (also
called digital books) and other forms of digital media such
as newspapers and magazines
 An e-book is an electronic version of a printed book,
readable on computers and other digital devices
 An e-reader can hold thousands of e-books
 Most e-readers have a touch screen and provide an on-
screen keyboard
 Some of them have built-in wireless technology to connect
to Internet
 An e-reader is usually smaller than a tablet and larger than
a smartphone

39. Uses of Computer
 Main fields where computers are playing a very important role are:
– Education
– Business
– Banks
– Departmental Stores
– Entertainment
– E-Commerce
– Health Care
– Science
– Publishing
– Travelling
– Government
– Home
– Agriculture
– Energy
– Library
– Defense
– Internet Details are given in book for each point

40.  Computer Aided Design vs Computer Aided
Manufacturing