Introduction to Computer
Learning outcomes
At the end of this module the student should be able to:
• Understand how computer work.
• Familiarize with the concept of hardware and software.
• Understand the concept of data processing and applications
• Know the generation/evolution of computer.
• Understand how computer play a role in every field of life.
• Identify input device, output device, and computer memory.
In today's world, we use computers for all our tasks. Our day-to-day activities: paying bills, buying
groceries, using social media, seeking entertainment, working from home, communicating with
a friend, etc., can all be done using a computer. So, it is important not only to know how to use
a computer, but also to understand the components of a computer and what they do.
This topic explains all concepts related to computer in detail, from origin to end. The idea of
computer literacy is also discussed, which includes the definition and functions of a computer.
You learn about the components of a computer, the concept of hardware and software,
representation of data/information, the concept of data processing and applications of IECT.
What is a Computer?
A computer is an electronic device that accepts data from the user, processes it, produces
results, displays them to the users, and stores the results for future usage.
Data is a collection of unorganized facts & figures and does not provide any further information
regarding patterns, context, etc. Hence data means "unstructured facts and figures".
Information is a structured data i.e. organized meaningful and processed data. To process the
data and convert into information, a computer is used.
Functions of Computers
A computer performs the following functions −
Receiving Input
Data is fed into computer through various input devices like keyboard, mouse, digital pens, etc.
Input can also be fed through devices like CD-ROM, pen drive, scanner, etc.
Processing the information
Operations on the input data are carried out based on the instructions provided in the programs.
Storing the information
After processing, the information gets stored in the primary or secondary storage area.
Producing output
The processed information and other details are communicated to the outside world through
output devices like monitor, printer, etc.
Sr.No. Computer Concepts & Description
1 History of Computers
The history of the computer dates back to several years. There are five prominent
generations of computers. Each generation has witnessed several technological
advances which change the functionality of the computers.
2 Characteristics of Computer System
Characteristics of Computer System involve Speed, Accuracy, Diligence, Versatility,
Reliability, Automation, Memory.
3 Basic Applications of Computer
Computers play a role in every field of life. They are used in homes, business,
educational institutions, research organizations, medical field, government offices,
entertainment, etc.
4 Components of Computer System
Computer systems consist of three components as shown in below image: Central
Processing Unit, Input devices and Output devices.
5 Input Devices – Keyboard and Mouse
Input devices help to get input or data from user.
6 Other Input Devices
There are few other input devices which help to feed data to the computer.
7 Output Devices
Output devices help to display output to user
8 Computer Memory
Computer memory refers to storage area where data is stored. It is of two
types Primary Memory & Secondary Memory.
9 Concept of Hardware and Software
The term hardware refers to mechanical device that makes up computer.
Software can be categorized into two types - System software & Application software
10 Programming Languages
The languages that are used to write a program or set of instructions are called
"Programming languages". Programming languages are broadly categorized into
three types - Machine level language, Assembly level language, High-level
language.
11 Representation of Data/Information
Computer does not understand human language. Any data, viz., letters, symbols,
pictures, audio, videos, etc., fed to computer should be converted to machine
language first. Computers represent that data into different forms.
12 Data Processing & Data Processing Stages
Data processing is a process of converting raw facts or data into meaningful
information.
13 Applications of IECT
IECT stands for Information Electronics and Communication Technology.
History of Computers
The history of the computer dates back to several years. There are five prominent generations
of computers. Each generation has witnessed several technological advances which change the
functionality of the computers. This results in more compact, powerful, robust systems which are
less expensive. The brief history of computers is discussed below −
First Generation (1940-1956)
The first generation computers had the following features and components −
Hardware
The hardware used in the first generation of computers was: Vacuum Tubes and Punch Cards.
Features
Following are the features of first generation computers −
It supported machine language.
It had slow performance
It occupied large size due to the use of vacuum tubes.
It had a poor storage capacity.
It consumed a lot of electricity and generated a lot of heat.
Memory
The memory was of 4000 bits.
Data Input
The input was only provided through hard-wired programs in the computer, mostly through
punched cards and paper tapes.
Examples
The examples of first generation computers are −
ENIAC
UNIVACTBM 701
Second Generation (1956-1963)
Several advancements in the first-gen computers led to the development of second generation
computers. Following are various changes in features and components of second generation
computers −
Hardware
The hardware used in the second generation of computers were −
Transistors
Magnetic Tapes
Features
It had features like −
Batch operating system
Faster and smaller in size
Reliable and energy efficient than the previous generation
Less costly than the previous generation
Memory
The capacity of the memory was 32,000 bits.
Data Input
The input was provided through punched cards.
Examples
The examples of second generation computers are −
Honeywell 400
CDC 1604
IBM 7030
Third Generation (1964-1971)
Following are the various components and features of the third generation computers −
Hardware
The hardware used in the third generation of computers were −
Integrated Circuits made from semi-conductor materials
Large capacity disks and magnetic tapes
Features
The features of the third generation computers are −
Supports time-sharing OS
Faster, smaller, more reliable and cheaper than the previous generations
Easy to access
Memory
The capacity of the memory was 128,000 bits.
Data Input
The input was provided through keyboards and monitors.
Examples
The examples of third generation computers are −
IBM 360/370
CDC 6600
PDP 8/11
Fourth Generation (1972-2010)
Fourth generation computers have the following components and features −
Hardware
The Hardware used in the fourth generation of computers were −
ICs with Very Large Scale Integration (VLSI) technology
Semiconductor memory
Magnetic tapes and Floppy
Features
It supports features like −
Multiprocessing & distributed OS
Object-oriented high level programs supported
Small & easy to use; hand-held computers have evolved
No external cooling required & affordable
This generation saw the development of networks and the internet
It saw the development of new trends in GUIs and mouse
Memory
The capacity of the memory was 100 million bits.
Data Input
The input was provided through improved hand held devices, keyboard and mouse.
Examples
The examples of fourth generation computers are −
Apple II
VAX 9000
CRAY 1 (super computers)
Fifth Generation (2010-Present)
These are the modern and advanced computers. Significant changes in the components and
operations have made fifth generation computers handy and more reliable than the previous
generations.
Hardware
The Hardware used in the fifth generation of computers are −
Integrated Circuits with VLSI and Nano technology
Large capacity hard disk with RAID support
Powerful servers, Internet, Cluster computing
Features
It supports features like −
Powerful, cheap, reliable and easy to use.
Portable and faster due to use of parallel processors and Super Large Scale Integrated Circuits.
Rapid software development is possible.
Memory
The capacity of the memory is unlimited.
Data Input
The input is provided through CDROM, Optical Disk and other touch and voice sensitive input
devices.
Examples
The examples of fifth generation computers are −
IBM
Pentium
PARAM
Characteristics of Computer System
The characteristics of the computer system are as follows −
Speed
A computer works with much higher speed and accuracy compared to humans while
performing mathematical calculations. Computers can process millions (1,000,000) of
instructions per second. The time taken by computers for their operations is
microseconds and nanoseconds.
Accuracy
Computers perform calculations with 100% accuracy. Errors may occur due to data
inconsistency or inaccuracy.
Diligence
A computer can perform millions of tasks or calculations with the same consistency and
accuracy. It doesn’t feel any fatigue or lack of concentration. Its memory also makes it
superior to that of human beings.
Versatility
Versatility refers to the capability of a computer to perform different kinds of works with
same accuracy and efficiency.
Reliability
A computer is reliable as it gives consistent result for similar set of data i.e., if we give
same set of input any number of times, we will get the same result.
Automation
Computer performs all the tasks automatically i.e. it performs tasks without manual
intervention.
Memory
A computer has built-in memory called primary memory where it stores data.
Secondary storage are removable devices such as CDs, pen drives, etc., which are also
used to store data.
Basic Applications of Computer
Computers play a role in every field of life. They are used in homes, business,
educational institutions, research organizations, medical field, government offices,
entertainment, etc.
Home
Computers are used at homes for several purposes like online bill payment, watching
movies or shows at home, home tutoring, social media access, playing games, internet
access, etc. They provide communication through electronic mail. They help to avail
work from home facility for corporate employees. Computers help the student community
to avail online educational support.
Medical Field
Computers are used in hospitals to maintain a database of patients’ history, diagnosis,
X-rays, live monitoring of patients, etc. Surgeons nowadays use robotic surgical devices
to perform delicate operations, and conduct surgeries remotely. Virtual reality
technologies are also used for training purposes. It also helps to monitor the fetus inside
the mother’s womb.
Entertainment
Computers help to watch movies online, play games online; act as a virtual entertainer
in playing games, listening to music, etc. MIDI instruments greatly help people in the
entertainment industry in recording music with artificial instruments. Videos can be fed
from computers to full screen televisions. Photo editors are available with fabulous
features.
Industry
Computers are used to perform several tasks in industries like managing inventory,
designing purpose, creating virtual sample products, interior designing, video
conferencing, etc. Online marketing has seen a great revolution in its ability to sell
various products to inaccessible corners like interior or rural areas. Stock markets have
seen phenomenal participation from different levels of people through the use of
computers.
Education
Computers are used in education sector through online classes, online examinations,
referring e-books, online tutoring, etc. They help in increased use of audio-visual aids in
the education field.
Government
In government sectors, computers are used in data processing, maintaining a database
of citizens and supporting a paperless environment. The country’s defense organizations
have greatly benefitted from computers in their use for missile development, satellites,
rocket launches, etc.
Banking
In the banking sector, computers are used to store details of customers and conduct
transactions, such as withdrawal and deposit of money through ATMs. Banks have
reduced manual errors and expenses to a great extent through extensive use of
computers.
Business
Nowadays, computers are totally integrated into business. The main objective of
business is transaction processing, which involves transactions with suppliers,
employees or customers. Computers can make these transactions easy and accurate.
People can analyze investments, sales, expenses, markets and other aspects of
business using computers.
Training
Many organizations use computer-based training to train their employees, to save money
and improve performance. Video conferencing through computers allows saving of time
and travelling costs by being able to connect people in various locations.
Arts
Computers are extensively used in dance, photography, arts and culture. The fluid
movement of dance can be shown live via animation. Photos can be digitized using
computers.
Science and Engineering
Computers with high performance are used to stimulate dynamic process in Science and
Engineering. Supercomputers have numerous applications in area of Research and
Development (R&D). Topographic images can be created through computers. Scientists
use computers to plot and analyze data to have a better understanding of earthquakes.
Components of Computer System
Computer systems consist of three components as shown in below image: Central
Processing Unit, Input devices and Output devices. Input devices provide data input
to processor, which processes data and generates useful information that’s displayed to
the user through output devices. This is stored in computer’s memory.
Central Processing Unit
The Central Processing Unit (CPU) is called "the brain of computer" as it controls
operation of all parts of computer. It consists of two components: Arithmetic Logic Unit
(ALU), and Control Unit.
Arithmetic Logic Unit (ALU)
Data entered into computer is sent to RAM, from where it is then sent to ALU, where rest
of data processing takes place. All types of processing, such as comparisons, decision-
making and processing of non-numeric information takes place here and once again
data is moved to RAM.
Control Unit
As name indicates, this part of CPU extracts instructions, performs execution, maintains
and directs operations of entire system.
Functions of Control Unit
Control unit performs following functions −
• It controls all activities of computer
• Supervises flow of data within CPU
• Directs flow of data within CPU
• Transfers data to Arithmetic and Logic Unit
• Transfers results to memory
• Fetches results from memory to output devices
Memory Unit
This is unit in which data and instructions given to computer as well as results given by
computer are stored. Unit of memory is "Byte".
1 Byte = 8 Bits
Concept of Hardware and Software
The concept of hardware and software is explained in detail below −
Hardware
The term hardware refers to mechanical device that makes up computer. Computer
hardware consists of interconnected electronic devices that we can use to control
computer’s operation, input and output. Examples of hardware are CPU, keyboard,
mouse, hard disk, etc.
Hardware Components
Computer hardware is a collection of several components working together. Some parts
are essential and others are added advantages. Computer hardware is made up of CPU
and peripherals as shown in image below.
Software
A set of instructions that drives computer to do stipulated tasks is called a program.
Software instructions are programmed in a computer language, translated into machine
language, and executed by computer. Software can be categorized into two types −
• System software
• Application software
System Software
System software operates directly on hardware devices of computer. It provides a
platform to run an application. It provides and supports user functionality. Examples of
system software include operating systems such as Windows, Linux, Unix, etc.
Application Software
An application software is designed for benefit of users to perform one or more tasks.
Examples of application software include Microsoft Word, Excel, PowerPoint, Oracle,
etc.
Differences between Software and Hardware are sorted out below −
Sr.No. Software Hardware
1 It is a collection of It includes physical components of computer
programs to bring system.
computer hardware
system into operation.
2 It includes numbers, It consists of electronic components like ICs,
alphabets, alphanumeric diodes, registers, crystals, boards, insulators,
symbols, identifiers, etc.
keywords, etc.
3 Software products Hardware design is based on architectural
evolve by adding new decisions to make it work over a range of
features to existing environmental conditions and time.
programs to support
hardware.
4 It will vary as per It is mostly constructed for all types of computer
computer and its built-in systems.
functions and
programming language.
5 It is designed and The hardware can understand only low-level
developed by language or machine language.
experienced
programmers in high-
level language.
6 The hardware works only on binary codes 1’s
It is represented in any
high-level language such
as BASIC, COBOL, C,
C++, JAVA, etc.
and 0’s.
7 The software is The hardware consists of input devices, output
categorized as operating devices, memory, etc.
system, utilities,
language processor,
application software, etc.
