There are three main ways to classify computers: by purpose, data processed, and size/speed. By purpose, there are general purpose computers designed for a variety of tasks and special purpose computers designed for a single task. By data processed, there are analog computers that measure data, digital computers that use binary, and hybrid computers that can do both. By size/speed, there are supercomputers that are the largest and fastest, mainframes for large organizations, mini computers for medium-sized uses, and microcomputers for personal use.

2. WE ARE LEARNING TO:
• A. STATE THE TYPES OF COMPUTER
• B. CLASSIFY COMPUTERS.
• (I) ACCORDING TO PURPOSE
• (II) ACCORDING TO SPEED/SIZE
• (III) ACCORDING TO DATA PROCESSED

3. TYPES OF COMPUTER
(ACCORDING TO DATA PROCESSED)
There are three types of computers.
This classification is based on how they work.
They are:-
• Analog computer
• Digital computer
• Hybrid computer

4. TYPES OF COMPUTER
Analog computer:
This is not a very common computer. It
works by measuring data. Examples are
thermometers, speedometer and electric
meter. They are used by scientist and
engineers. They are used for measuring
temperature, speed and current.

5. TYPES OF COMPUTER
DIGITAL COMPUTERS:-
They accepts data in binary form (0s and 1s).
They work by counting data. Most computers are
digital computers. Other devices that work like
digital computers are calculators, most resent car
speedometers, electronic watch and stop watch.

6. TYPES OF COMPUTER
HYBRID COMPUTERS:-
Is a digital computer that accepts analog
signals and converts and processes them into
digital form. They work like both analog and
digital computers. They work by measuring
and also by counting data. It is the type used
for space exploration, like going to the moon.

7. CLASSIFICATON OF COMPUTER ACCORDING
TO SIZE AND SPEED.
There are four different size of computer. They are:-
•SUPER COMPUTER:-
This is the biggest, most powerful and the
fastest computer. It is as big as room. A
supercomputer is used in weather
forecasting, nuclear power stations,
military simulation, research laboratories
and animation movies.

8. CLASSIFICATON OF COMPUTER ACCORDING
TO SIZE AND SPEED.
•MAINFRAME COMPUTER:
This is a large computer with a huge storage capacity.
It is used in large business or in government
organization to perform complex tasks. Bulk data
processing such as census, industry and consumer
statistics, enterprise resource planning, and
transaction processing.It is as big as a closet.
They are mostly used for scientific research purposes.

9. CLASSIFICATON OF COMPUTER ACCORDING
TO SIZE AND SPEED.
• MINI COMPUTER:-
This is smaller than mainframe computer but bigger than
microcomputer. It can be used by many people at the same
time. It is not as expensive as mainframe. It is not as fast as
mainframe. It is used in universities, polytechnics, companies
etc.
It is about the size of a refrigerator.
It is used for scientific research, and also in places like banks
and large organisations.

10. CLASSIFICATON OF COMPUTER ACCORDING
TO SIZE AND SPEED.
• MICROCOMPUTER:-
It is the smallest type of computer. It is not as fast
and costly as mini computers. It can be used at homes,
offices, school etc. It can serve only one person at a time
and so can be called personal computer.
Peripherals such as keyboard, mouse, monitor and
system unit are parts of the microcomputer system.
Types of microcomputer
Desktop computer Laptop computer
Palmtop/hand
held computer

11. CLASSIFICATION OF COMPUTER
BY PURPOSE:
Computer can be categorized by its
purpose. There are two main purposes of
a computer. These purpose are “special
and “general”.

12. CLASSIFICATION OF COMPUTER
BY PURPOSE:
• GENERAL PURPOSE COMPUTER:-
This are designed to solve a large variety of
problems. Example is microcomputer
which can be used for word processing,
spreadsheet, database, games,
communication and other jobs.

13. CLASSIFICATION OF COMPUTER
BY PURPOSE:
• SPECIAL PURPOSE COMPUTER:-
These computers are made for one particular
purpose. Example is a word processor computer
which can only be used for typesetting of
documents. The computer that landed man on
the moon was specially built for that purpose.
Robots are special computer built to do what man
could have been doing by himself.

14. REVISION QUESTIONS
• A road traffic control computer is an example of ____computer (a) general purpose
(b) microcomputer (c) special purpose.
• ______Computers are designed for a particular work . (a) General purpose (b) Analog (c) Special purpose
• Which among these is the fastest in processing data?. (A) Manual (b) Electronic
(c) Computer
• List 3 types of computer.
• Mention two computers each under the following classification of computer.
i. According to purpose
ii. According to data processed
iii. According to size.