A computer is an electronic device that manipulates data through processes like storage, retrieval, and processing. It has four main components: input devices, output devices, a central processing unit (CPU), and storage devices. The CPU acts as the brain and controls all parts of the computer. It performs arithmetic, logical, and control functions. Storage devices include primary memory like RAM and ROM for temporary and permanent storage, as well as secondary memory like hard disks for large-term storage. Computers have had a large impact on daily life by automating tasks, facilitating communication and access to information, but also by enabling issues like data theft and a changing job market.

1. INTRODUCTION TO
COMPUTERS
INFORMATION TECHNOLOGY
P.W.G.T.BANDARANAYAKE
IT INSTROCTOR OF MAWATHAGAMA

2. WHAT IS A COMPUTER?
A computer is an electronic device that
manipulates information, or data. It has the ability
to store, retrieve, and process data.

3. Function of computer

4. What is Data ?
Data can be defined as a representation of facts, concepts, or
instructions in a formalized manner,
What is Processing ?
In this step, the input data is changed to produce data in a more useful
form. For example, pay-checks can be calculated from the time cards, or a
summary of sales for the month can be calculated from the sales orders.
What is Information?
Information is organized or classified data, which has some meaningful
values for the receiver. Information is the processed data on which
decisions and actions are based.

5. Overview of a Personal Computer

6. Characteristics of a computers

7. Computer System

8. COMPUTER HARDWARE

9. 1. Input Devices
2. Output Devices
3. Central Processing Unit
4. Storage Devices
* Primary Storage
* Secondary Storage
Components of the computer can be
categorized into four groups

10. Input Devices
• Input device Translate data from form that humans understand to one
that the computer can work with

11. OUTPUT DEVICES
An output device is
any piece of
computer hardware
equipment used to
communicate the
results of data
processing carried
out by an
information
processing system

12. Think about this ???

13. Central Processing Unit (Brain of the computer)
Input
Output
Storage
Central Processing Unit
Arithmetic & Logical Unit
Memory Unit
Control Unit

14. CPU is considered as the brain of the computer. CPU performs all types of
data processing operations. It stores data, intermediate results, and
instructions (program). It controls the operation of all parts of the computer
• The arithmetic-logic unit (ALU) is
that functional part of the digital
computer that carries out
arithmetic and logic operations
on machine words that represent
operands. In many CPUs,
separate units exist for
arithmetic operations (the
arithmetic unit, AU) and for logic
operations (the logic unit, LU).
The control unit (CU) is a
component of a computer's
central processing unit (CPU) that
directs the operation of the
processor. ... It directs the flow of
data between the CPU and the
other devices. John von Neumann
included the control unit as part of
the von Neumann architecture.

15. STORAGE DEICES (Primary , Secondary memory)
RAM ROM
Primary Memory
• Main working Memory
• Specific contents can be
accessed (read or written)
directly by the CPU in a very
short time
• At the time computer is
“ON”, it is copied to the
RAM
• Volatile
Random Access Memory (RAM)
Read Only Memory (ROM)
• Memory Chip
• Read
• Write
• Nonvolatile
• ROM-BIOS
• Contain read-only software
that start up the computer

16. Secondary Memory (Secondary/Auxiliary
memory/Backing Storage)

17. Generations of Computers
1st Generation  Vacuum tubes
2nd Generation  Transistor
3rd Generation  Integrated circuits
4th Generation  Microprocessors
5th Generation  Artificial intelligence.

18. • According to the purpose of the computer.
General purpose computers.
Special purpose computer.
Classification of Computers
• According to the operation of computer
Digital Computers
Analog Computers
Hybrid Computers
• According to the size of computer
Super Computers
Mainframe Computers
Minicomputers
Desktop Computers
Laptops
Notebooks
Personal Digital Assistants (PDAs)
Tablet Computers
Smart phones

19. Unit of Measurements
Computer Storage unit
Speed measurement

20. Importance of IC
In formation and Communication
Technology (ICT) is such an integral part
of our lives that it is embedded in all
areas

21. ICT related fields
• Education
• Business applications
• Banking
• Office Automation
• Desktop publishing
• Science research
• Management aids
• Engineering designing
• Road traffic control
• Railway
• Medicine
• Information services

22. Impact of computers on daily life
Positive Impact
• We can perform multitasking and multiprocessing
capabilities of data.
• It is very easy to access and use data for business
application.
• We can store documents secretly on computer
system.
• It gives error free result so that we can use it for
research, engineering work and other areas.
• It can be used for various purposes like education,
business, industries etc.
• It is used for communication system also. Use of
Internet, Email and Internet phone system.
• It helps to automate the office and business process.
Negative Impact
• It is an expensive system so people may not be able
to afford it and use this system that creates digital
divide on society.
• It encourages and facilities for data piracy.
• It has bad impact on job market. It may increase
unemployment.
• Chances of data stolen and hacking that destroys
data.
• It is fast changing technology so it is required to be
updated timely.
• It facilitates computer crime and cyber theft.

23. THANK YOU
GOOD LUCK ALL OF YOU