We educate and prepare the candidates to achieve their goals in the Public Sector areas. We provide them comprehensive details and knowledge required to crack any Competitive Exams from Base building to their Final Selection.

1. COMPUTER
General Introduction
By Krishna Jani

2. GENERAL INTRODUCTION
 The word ‘computer’ has been derived from the Latin word
‘computerae’ meaning ‘to compute’.
 A computer is a man made electronic machine which
stores, reads and processes data to produce meaningful
information as output.
 Actually, a computer is a collection of hardware and
software components that helps us to accomplish many
different tasks.
KRISHNA JANI

3. HARDWARE
 Hardware consists of computer itself and includes
 A CPU
 A Monitor
 A Keyboard
 A Mouse
 And any equipment connected to it.
KRISHNA JANI

4. A CPU
KRISHNA JANI

5. A MONITOR
KRISHNA JANI

6. A KEYBOARD
KRISHNA JANI

7. A MOUSE
KRISHNA JANI

8. HUMAN V/S COMPUTER
Human Being Computer
Slow in Calculation Do complex calculations in seconds
Cannot remember lots of things at
one time
Can store and remember a large
amount of information at one time
Can make mistakes Do not make mistakes
Have feelings Do not have feelings
Can think Cannot think
Get tired if they work for long
hours
Never get tired
KRISHNA JANI

9. ELEMENTARY WORDS RELATED TO
COMPUTER
Data
Numeric
Data
Alphabetic
Data
Alphanumeric
Data
Information
KRISHNA JANI

10. ……CONTINUE
Data :
Data is information required by the computer to be able to operate
or to put it the other way we put into the computer is called Data. It is a
collection of unprocessed items and combination of characters, numbers
and symbols collected for a specific purpose.
 Numeric data
Numeric data consists of ten digits 0,1,2,3,4,5,6,7,8,9.This
data includes decimal number system, binary number system ,octal
number system and hexadecimal number system.
e.g . Exam score, bank balance , pin-code
KRISHNA JANI

11. ……CONTINUE
 Alphabetic Data
alphabetic data is used to represent 26 alphabets. It consist of
capital letters from ‘A to Z ‘, small letters from ‘a to z’ and blank space. It is also
called non-numeric data.
e.g. Name.
 Alphanumeric Data
Alphanumeric data is used to represent alphabetic data ,
numeric data , special characters and symbols.
e.g. password , email-id
Information
Information is well organized data which we get after processing
of data and it helps in decision making. It is processed data that is organized ,
meaningful and useful .
KRISHNA JANI

12. CHARACTERISTICS OF COMPUTER
 Speed : A computer is a very fast and accurate device. It
takes only few seconds to process the instructions for
which we take hours to complete.
Processing speed :- Bank , stores , stock exchange , reservation
 Accuracy and Reliability
Errors are caused by humans , not by computers.
 High Storage Capacity
storing enormous amounts of data that must be located and
retrieved very quickly.
KRISHNA JANI

13. ……CONTINUE
 Automation
Once a process has been initiated, it is capable of functioning
automatically.
 Diligence
It is capable of operating at exactly the same level od speed and
accuracy even if it has to carry out most voluminous and complex operation
for a long period of time.
 Versatility
The wide use of computer is used in so many areas.
KRISHNA JANI

14. USES OF COMPUTER
Entertainment or
Recreation
Education
Banks
Railway Stations and
Airport
Medical Science
Business
Defence
Designing
Scientific Research
Administration
Publication
Communication

15. LIMITATION OF COMPUTER
Lack of Intelligence
(Programmed by Human)
Cannot think
Prone to virus
Depends on Electricity
KRISHNA JANI

16. FUNCTIONS OF COMPUTER
Data Collection
Data Storage
Data Processing
Data Output
KRISHNA JANI

17. IMPACT OF COMPUTERIZATION
Time Saving
Errorless work
Saving of paper
KRISHNA JANI

18. DATA PROSSESING
 In the past , manual techniques used for collecting ,
manipulating and distributing data to achieve certain
objectives , were known as Data Processing .
 As technology advances , computers are used to achieve
results accomplished by humans and machines.
 The major objective of data processing is to get the desired
information from any row data.
 This helps in decision making.
 Processing involves transforming input into output.
KRISHNA JANI

19. COMPUTER SYSTEM
A group of equipment put together to process a data is called
a computer system.A computer consists of several components to
achieve electronic data processing.
 Input Units
which accept data from user and transmit it to the
central processing .
 CPU (Central Processing Unit)
is the brain of the computer . CPU is the unit where
most calculations take place.
KRISHNA JANI

20. INSTRUCTION CYCLE
KRISHNA JANI

21. ……CONTINUE
 Fetch the instruction
CPU fetches the instruction from main memory.
 Decode the instruction
The instruction decoder interprets instructions.Address of the
instruction read from main memory to be processed and then
placed into data register.
 Execute the instruction
The control unit passes the decoded information as a sequence of
control signals to the relevant function unit.
 Store Result
The result generated by the operation is stored in the main
memory or sent to an output device .
KRISHNA JANI

22. MAIN COMPONENTS OF CPU
Arithmetic Logic
Unit
Control Unit
Main Memory
Output UnitInput Unit
KRISHNA JANI

23. .......CONTINUE
 There are two main components of CPU
 ALU ( Arithmetic Logic Unit)
It performs all arithmetic operations and decision making
operations.
DataTransfer : includes moving of data from one location to
another within the computer .
Arithmetic Operation : includes addition , subtraction ,
multiplication and division etc.
Decision Making
It is an ability to compare two quantities and perform
logical operations such as compare , true or false etc.
 Control Unit : It extracts instructions from memory and execute
them , calling on the ALU , when needed.
KRISHNA JANI

24. FUNCTIONS OF CONTROL UNIT
 Control Flow of Data
From input devices to memory
From memory to output devices or secondary Storage
From ALU to memory
From memory to ALU
 Co-ordinates instructions execution
Fetch the instruction
Decode the instruction
Execute the instruction
 Output Units
Devices which accept information from CPU and convert it to
human readable form .e.g receipt from printer
KRISHNA JANI

25. KRISHNA JANI