2. INTRODUCTION TO COMPUTERS
•What is a computer? A computer is an
electronic device that manipulates
information or data. It can store, retrieve and
process data.
3. HISTORY OF COMPUTERS
• Generally speaking, computers can be classified into three generations. Each generation
lasted for a certain period of time, and each gave us either a new and improved computer or
an improvement to the existing computer. First generation: 1937 – 1946 - In 1937 the first
electronic digital computer was built by Dr. John V. Atanasoff and Clifford Berry. It was called
the Atanasoff-Berry Computer (ABC). In 1943 an electronic computer name the Colossus was
built for the military. Other developments continued until in 1946 the first general– purpose
digital computer, the Electronic Numerical Integrator and Computer (ENIAC) was built. It is
said that this computer weighed 30 tons, and had 18,000 vacuum tubes which was used for
processing. When this computer was turned on for the first time lights dim in sections of
Philadelphia. Computers of this generation could only perform single task, and they had no
operating system.
4. HISTORY OF COMPUTER CONT’D
• Second generation: 1947 – 1962 - This generation of computers used
transistors instead of vacuum tubes which were more reliable. In 1951 the
first computer for commercial use was introduced to the public; the Universal
Automatic Computer (UNIVAC 1). In 1953 the International Business Machine
(IBM) 650 and 700 series computers made their mark in the computer world.
During this generation of computers over 100 computer programming
languages were developed, computers had memory and operating systems.
Storage media such as tape and disk were in use also were printers for
output
5. HISTORY OF COMPUTERS
• Third generation: 1963 - present - The invention of integrated circuit
brought us the third generation of computers. With this invention computers
became smaller, more powerful more reliable and they are able to run many
different programs at the same time. In1980 Microsoft Disk Operating
System (MS-Dos) was born and in 1981 IBM introduced the personal
computer (PC) for home and office use. Three years later Apple gave us the
Macintosh computer with its icon driven interface and the 90s gave us
Windows operating system.
6. FUNCTIONS OF A COMPUTER
• Input and Output- Communication with the outside world takes place through
the input and output elements of the computer system. Data is input into a
computer through external hardware devices like mice, keyboards, touchscreens
and storage devices. Once data has been processed, it can be converted to a
human-readable format for output to devices like printers, displays, speakers or
headphones. The computer can also convert data to other output formats, such
as electrical signals for controlling automated equipment.
7. FUNCTIONS OF A COMPUTER CONT’D
• Storage Memory- computers use both internal and external memory
when performing operations. Internal memory is used to hold the software
instructions and related data for programs that are currently executing. Internal
memory consists of RAM (random access memory), which is temporary because it
retains data only while power is applied. When the computer is turned off, the
memory clears. Data which is not being used by the computer is usually stored in
external memory on devices like hard drives and flash drives.
8. FUNCTIONS OF A COMPUTER CONT’D
• Data processing is the core function of a computer. Processing
involves manipulation of raw data into before converting it into
meaningful information. Usually, data is in raw form, and will thus
undergo processing before dissemination for user consumption.
• The 'brain' of the computer where data is processed is referred to as
the microprocessor. It is also commonly known as the central
processing unit (CPU) or accelerated processing unit (APU).
9. COMPONENTS OF A COMPUTER
• Datapath - manipulates the data coming through the processor. It also provides a
small amount of temporary data storage.
• Control - generates control signals that direct the operation of memory and the
datapath.
• Memory - holds instructions and most of the data for currently executing
programs.
• Input - external devices such as keyboards, mice, disks, and networks that provide
input to the processor.
• Output - external devices such as displays, printers, disks, and networks that
receive data from the processor.
11. ADVANTAGES OF A COMPUTER
Multitasking is one of the major advantage of computer. Person can perform
multiple task, multiple operation, calculate numerical problems within few
seconds. Computer can perform trillion of instructions per second.
Speed- now computer is not just a calculating device. Now a day’s computer has
very important role in human life. One of the main advantages of computer is its
incredible speed, which helps human to complete their task in few seconds. All
the operations can be performed very fast just because of its speed elsewise it
takes a long time to perform the task.
12. ADVANTAGES OF A COMPUTER
Cost/ Stores huge amount of data- It is a low cost solution.
Person can save huge data within a low budget. Centralized
database of storing information is the major advantage that
can reduce cost.
Accuracy- One of the root advantage of computer is that can
perform not only calculations but also with accuracy.
13. DISADVANTAGES OF A COMPUTER
Virus and hacking attacks- Virus is a worm and hacking is simply an unauthorized access over
computer for some illicit purpose. Virus is being transferred from email attachment, viewing an
infected website advertisement, through removable device like USB etc. once virus is transferred in
host computer it can infect file, overwrite the file etc.
Online Cyber Crimes- Online cyber-crime means computer and network may have used in order to
commit crime. Cyberstalking and Identity theft are the points which comes under online cyber-crimes.
For example: one may get the access of the access to your shopping account like amazon account
now that person will be able to know your personal details like debit card or credit card number which
can be than misused.
14. DISADVANTAGES OF A COMPUTER
Reduction in employment opportunity- Mainly past
generation was not used of the computer or they have the
knowledge of computer they faced a big problem when
computer came in field. As we have seen in banking sector
senior bank employees faced this problem when computer
came to the banking sector.
15. THE USES AND EFFECTS OF COMPUTERS
ON SOCIETY
• The widespread adoption of computers has had lots of effects on society. First of
all, it has impacted the way that we shop and make purchases. In some ways this
change is positive, since the rise of online retailers like Amazon has given us
greater choice as consumers over where we buy our goods. It also means that
we can make purchases without having to leave the house. However, the ability
to do our shopping online has affected physical stores by increasing the
competition between companies.
16. EFFECTS OF COMPUTERS ON SOCIETY
CONT’D
• In addition, computers have also changed the way we communicate
with each other. The rise of email and social media networks, for
example, has made it easier than ever for people to stay in touch
with family and friends and to meet new people. Moreover, access
to these services is free, making online communication a far cheaper
alternative to sending letters or making phone calls.
17. EFFECTS OF COMPUTERS ON SOCIETY
CONT’D
• Computers have changed the way information is saved and accessed. Now with
a few clicks on a computer, people can access almost any piece of information.
The speed at which people can access information has never been faster. We
can say that the computer has democratized almost all information. This point
cannot be overemphasized. computers have changed warfare. Now people use
computers to conduct war in many ways. The threat of cyber-warfare is real and
even within the past few years, many hackers have tried to break into our
military systems. This area will certainly grow in the future.
18. WHO IS A COMPUTER USER?
• A computer user is a
person who uses
computers for work or
entertainment or
communication or
business
19. TYPES OF USERS
System accounts- These accounts are used by different services
running in operating system to access the system resources.
Operating system uses these accounts to check whether a particular
service which is requesting for system resources is allowed to access
those resources or not. Usually services create necessary accounts
on their own when they are installed. After installation, services use
these accounts to access necessary resources. Unless you are a
system or network administrator, you never need to know about
these accounts.
20. TYPES OF USERS
Super user account- This user account has the highest privilege in
operating system. In Windows, this user account is known as
Administrator account. In Linux it is known as root account. Operating
system allows this user account to perform all privileged tasks such as
changing system files, installing new software, removing existing
software, starting services, stopping services, creating new user
accounts and deleting existing user accounts.
21. TYPES OF USERS
Regular user account- This user account has moderate privilege. This user
account is not allowed to make any change in system files and properties.
Operating system allows this user account to perform only the tasks that it is
authorized to do such as creating files and folders, running applications,
customizing environmental variables, etc.
Guest user account- This user account has the lowest privilege. It can’t make any
change in any system files or properties. Usually this account is used to access the
system for temporary tasks such as suffering internet, watching movies, playing
games etc. In Windows, this account is automatically created during the
installation. In Linux, if require, we have to create this account manually after the
installation.
22. TYPES OF USERS
User account vs Group account- User account is an individual identity of a
user while group account is the collective identity of all users those belong to
a specific group. Grouping helps system administrators in managing system
effectively. For example, in a company all the users of the development
department may belong to a group called developers. Once group is created,
administrator can create and configure several security rules and applications
to ensure that only the users from developers group access the development
department’s resources such as SQL server, Language API, source code
compiler, etc.
23. INTERNET TOOLS
Internet Tools are electronic instruments based on internet
technology with which parties can interact (e.g., Intranet,
extranet, Web page, e-mail, videoconference, and
discussion groups).
24. THE MAJOR INTERNET TOOLS
1. Electronic mail (email)
2. World Wide Web (www)
3. Internet Relay Chat (IRC)
4. File Transfer Protocol (FTP)
5. New Group
6. Telnet
26. COMPUTER HARDWARE
• Computer hardware refers to the physical parts of a computer and
related devices. Internal hardware devices include motherboards,
hard drives, and RAM. External hardware devices include monitors,
keyboards, mice, printers, and scanners. The internal hardware parts
of a computer are often referred to as components, while external
hardware devices are usually called peripherals. Together, they all
fall under the category of computer hardware.
27. COMPUTER SOFTWARE
• Computer Software, in its most general sense, is a set of
instructions or programs instructing a computer to do
specific tasks. Software is a generic term used to describe
computer programs. Scripts, applications, programs and a
set of instructions are all terms often used to describe
software.
28. CATEGORIES OF A HARDWARE
Hardware devices can be classified into four distinct categories:
Input Devices- components which are used to input raw data are
categorized under input devices. They aid in feeding data such as
text, images, and audiovisual recordings. They even aid in file
transfers between computers. The keyboard is probably the most
commonly used input device. Below are just some other types of
input devices. Other examples include: Game controller, web cam,
microphone.
29. CATEGORIES OF HARDWARE CONT’D
• Processing Devices- Processing is the core function of a
computer. It is the stage where raw data is transformed
into information. Once data has been processed, it can be
used for useful purposes. Components that manipulate
data into information are categorized under processing.
Examples include; the control unit, Arithmetic and logic
unit.
30. CATEGORIES OF HARDWARE CONT’D
• Output Devices- Hardware components that disseminate and display both data
and information are classified under the output category. Output is the
culmination of a cycle which starts with the input of raw data and processing.
These components are sub-categorized under softcopy and hardcopy output.
Softcopy output includes the intangible experience. The user derives visual
satisfaction by reading a message through display components or listens to audio
files through speakers. On the other hand, hardcopy output devices are tangible,
like printouts of paper and 3D models.
31. CATEGORIES OF HARDWARE CONT’D
• Memory/Storage Devices- Components that retain/store data are classified
under memory/storage devices. Storage is sub-divided under primary
and secondary memory and is either volatile or nonvolatile. Primary
memory usually refers to random-access memory (RAM) but can also
refer to all memory that works in tandem with the processor. RAM is
volatile, meaning that it retains data only when the computer is
powered up. The central processing unit (CPU) or accelerated
processing unit (APU) reads instructions stored in this memory and
executes them as required.
32. CATEGORIES OF SOFTWARE
Software is often divided into three categories:
System software serves as a base for application software. System
software includes device drivers, operating systems (OSs),
compilers, disk formatters, text editors and utilities helping the
computer to operate more efficiently. It is also responsible for
managing hardware components and providing basic non-task-
specific functions. The system software is usually written in C
programming language.
33. EXAMPLES OF SOFTWARE AND
HARDWARE
SOFTWARE
• Antivirus
• E-mail
• Operating System
• Movie Player
• Internet Browser
HARDWARE
• Motherboard
• Keyboard
• Monitor
• Printer
• Screen
34. CATEGORIES OF SOFTWARE CONT’D
Programming software is a set of tools to aid developers in writing
programs. The various tools available are compilers, linkers,
debuggers, interpreters and text editors.
Application software is intended to perform certain tasks.
Examples of application software include office suites, gaming
applications, database systems and educational software. Application
software can be a single program or a collection of small programs.
This type of software is what consumers most typically think of as
"software."