Introduction to computer

 Skills that span different aspects of life

 Easy Access to information

 Greater Self Efficiency and Sufficiency

 Improved Employment Prospect

CRT Display
Keyboard
Mouse
Casing
CD-ROM Drive
Floppy
Disk
Drive
USB Port
University of Rajshahi
Dept. of Computer
Science & Engineering

Computer - the word
• The first use of the word “computer” was recorded in 1613 in a
book called “The yong mans gleanings” by English writer
Richard.
• The writer used the word computer to refer a person who
carried out calculations, or computations, and the word
continued with the same meaning until the middle of the 20th
century.
• From the end of the 19th century the word began to take on its
more familiar meaning, a machine that carries out
computations.

What is Computer?
• A computer is an electronic device that can receive data as
input, process the received data and convert it into meaningful
information as output, which is useful to people.
• It has the ability to store, retrieve, and process data.
• Charles Babbage is Considered as the father of the computer.
Babbage is credited for inventing the first mechanical
computer.
• ENIAC(Electronic Numerical Integrator And Computer)
was the first electronic general-purpose computer. It was
digital and capable of being reprogrammed to solve a full range
of computing problems.

Charles Babbage (26 December 1791 –
18 October 1871)
An English man known for mathematics
and computer science
ENIAC was initially designed to
calculate artillery firing tables
for the United States Army.
It was then announced as
“Giant brain”

What is Computer?
 It performs the following four actions:
1. Receive Input
2. Processing
3. Produce Output
4. Store
 The above four operations together is called information
processing cycle

Information-processing cycle
PROCESSING OUTPUT
STORAGE
INPUT

Definitions
 Input: User gives instruction to the computer in the form of
input. Devices that enable the user to enter data into the computer
for processing are called input device. In other words device that is
used to give input is called input device. Examples: mouse and
keyboard
 Processing: converts input into output
 Output: Computer provides the results of the processed
instruction or operation in the form of output that people can
understand easily. Devices that enable the user to receive
information from the computer after processing called output
device. In other words device that is used to give output is called
output device. Examples: monitor and printer
 Storage: Computer saves the processed result into the storage to
use again later for both the user and the computer. Storage devices
hold all of the programs, data and information. Examples: hard disk

The Parts of A Computer System
 A computer system consists of four basic units:
1. Hardware
2. Software
3. Data
4. Users

Hardware
 The mechanical devices that make up the computer are called
hardware. Hardware is any part of your computer that has a
physical structure
 Hardware is tangible. In other words any part of the computer
that you can touch is hardware.
 All the input and output devices are the example of hardware
 Examples : monitor, keyboard, mouse, speaker, scanner

Different forms
of
computer hardware

Software
 Software is a set of instructions that makes the computer
perform tasks. A software tells the computer what to do, when
to do and how to do. It is intangible.
 A software should have the following characteristics:
1. It is a collection of executable instructions
2. It must manipulate data
3. It should have proper documentation about how to use it
 Some examples of software are web browsers, games, and word
processors such as Microsoft Word.
 Other examples: MS word, windows media player, IE, Firefox,
avast antivirus, vlc player, win amp.

Different forms
of
computer software

Data
 Data mean raw, unorganized and unprocessed facts.
 The word data is the plural of Latin word datum which means
“something given”
 The primary job of a computer system is to process tiny pieces
of data in various ways and convert them into useful
information.
 Information means the processed or meaningful data.

User
 An user is an entity who uses the computer system.
 Computer users can be divided into five categories:
1. Home user
2. Small office/home office users
3. Mobile users
4. Large business users
5. Power users.

Types of User
 A home user: spends time on the computer for personal and
business communications, personal financial management,
entertainment, and Web access.
 A small office/home office (SOHO): user includes any company
with fewer than 50 employees, as well as self-employed people
that work out of their home.
 A mobile user :travels to and from a main office or school to
conduct business, communicate, or do homework.
 A large business user: works for a company that has a large
number of employees and computers usually connected to a
network.
 The power user : such as an engineer, architect, or desktop
publisher – typically works with multimedia, which combines
several media elements into one application, and requires the
capabilities of a workstation or other powerful computer.

Difference between hardware and
software
1. Software is intangible but hardware is tangible
2. Software is developed or engineered, but not manufactured
in the classical sense. While hardware is mainly
manufactured
3. Software doesn't "wear out” but hardware does
4. Although the hardware industry is moving toward
component-based assembly, most software continues to be
custom built.

Basic Components of Computer
 A computer is a programmable electronic device that can
receive data as input, process the received data and convert it
into meaningful information as output, which is useful to people.
It can also communicate with other devices or computers. It is a
high speed electronic machine or data processing machine.
 Basic components of a computer:
1. Input Unit
2. Memory Unit
3. Control Unit
4. Arithmetic Logic Unit
5. Output Unit
6. Communication Unit
Central Processing Unit -CPU

CCoommmmuunniiccaattiioonn U Unniitt
IInnppuutt U Unniitt MMeemmoorryy U Unniitt OOuuttppuutt U Unniitt
Control Unit AL Unit
Central Processing Unit [CPU]

 Input Unit: input unit accepts data from the user or the input
devices and transfers it to the memory unit. Input devices are
keyboard, mouse, scanner, digital camera.
 Memory Unit: the function of memory unit is to store data and
information received from the input devices. It also supplies data
and information to the output unit or to the arithmetic logic unit.
Two basic types of memory are: RAM and ROM.
 Control Unit: control unit is the basic controller of the computer
system. The main function of control unit is to control all the
resources of a compute system. It works as the traffic controller of
a computer system. It tells the input unit when to receive data
from input devices and the output unit when to display a
particular information. Any operation that is performed by
computer system is performed as the direction of the control unit.

 Arithmetic Logic Unit: it is computer’s calculator or brain that
performs all the arithmetic operations such as addition,
subtraction, multiplication and division as well as all the logical
operations such as AND, OR, NOT etc. It is the data processing unit
of the processor or CPU or in other words computer .
 Output unit: the function of output unit is to display or show the
result or processed data to the user. Examples: monitor, printer.
 Communication Unit: the function of communication unit is to
perform communication between two or more computers.
Examples: hub, switch, modem etc.

How to decide When Buying A Computer
1. Buy based on what you need it for, plus a little more
2. Consider your budget
3. Do your research
4. Know the software inclusion

 Buy based on what you need it for, plus a little more:
 One of the most important considerations when buying a
computer is to see what exactly you will use it for. Models of
computers come with different capabilities that there is always
a possibility of buying more or less than you really need.
 Some uses include: connecting to the Internet, playing games,
typing documents, designing websites, programming, digital
video or photography, digital scrapbooking, among others.
 Some of these need more computing power than others, so be
sure how you will use the computer . As a rule of thumb, it is
best to buy a little more power than you need, but not far more
as it will simply be a waster of money.

 Consider your budget:
 Once you find out exactly what you would be needing your
computer for and the range of specifications that you need your
computer to have, consider the amount of money you can afford
to spend.
 One should compromise on the main parts such as the
processor, memory and hard disk space, as this primarily
dictates the performance that your system will promise.
 Remember that you will be using this system for three or more
years. If you do not have enough budget, put off buying a
printer or other unnecessary software applications instead.

 Do your research: Do not buy the first computer that you see.
Gather as much information as you can on the computers that
best fits your budget and needs. Try to learn computer
terminologies so that you will have an idea about the details
that your salesman is talking about.
 Know the software inclusion: The last consideration in
buying a computer is the software included in the bundle (aside
from the Operating System, of course). The most important
programs that you would need would be: MS Office, antivirus
and firewall. Watch out for trial or limited versions as they do
not include the full functionality of the program. Always ask
your salesperson about the software included and its versions.

10 Things To Consider When Buying A
Computer
1. Usability or users demand
2. Price
3. Operating system type
4. Size of the computer system
5. Peripherals (like scanners, printers)
6. Brand of components (like dvd of sony or asus)
7. Hard disk
8. Ram
9. processor
10. warranty

What is Ergonomics
 Ergonomics is the study of the physical relationship between
people and their tools like computer.
 Ergonomics is to design tools to make it working properly
with the human body and thus reduce the risk of strain and
injuries.
 The purpose of ergonomics is to develop or design user
friendly tools or devices for human use.

References
1. Peter Norton's Introduction to Computers, Sixth Edition
2. en.wikiperdia.org

MD. Shakhawat Hossain
Student of Computer Science & Engineering Dept.
University of Rajshahi

Introduction to computer

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