Computers can be classified in several ways: by purpose as general purpose or special purpose computers, by technology as analog, digital or hybrid, and by size and capacity as super computers, mainframe computers, mini computers or micro computers. General purpose computers are used for a variety of tasks in homes and offices while special purpose computers perform specialized tasks. Digital computers represent data with binary digits and are commonly used today, while analog computers were used for scientific problems. Hybrid computers combine analog and digital elements. Classification by size ranges from very large super computers for complex tasks, to mainframe, mini then micro computers which are small, low-cost personal computers.

1. CLASSIFICATION OF COMPUTER
EHTASHAM UL HAQ
LECTURE NO 2
GOVT. COLLAGE HAYATABAD

2. CLASSFICATION OF COMPUTER
Types of
Computers
On the
basis of
Purpose
On the basis
of Technology
On the basis of
size & Capacity
General
purpose
Special
Purpose
Analog
Digital
Hybrid
Super
computer
Mainframe
computer
Mini
computer
Micro
computer

3. On the basis of purpose
General purpose computer
 They are used to perform a variety of tasks
 They are used in solving a business problem as well as mathematical
equation with same accuracy and consistency .
 They are Generally found in home and offices.
 Their uses include preparation of documents ,letters ,reports, financial
analysis ,data recording and analysis etc.

4. Special Purpose computers
 Special purpose computers are designed to perform only
specialized task for which they are meant.
 Example weather forecasting, space research ,air traffic control
,medical diagnostic etc.

5. ANALOG COMPUTER
 Analog computer were commonly used for scientific & engineering problems, particularly in
chemical industry, electric power plants, and petroleum refineries.
 These type of computers are rarely use in current world. For Example:
 Electric current meter, Fuel pump station meters etc.

6. Digital Computer
 They represent data, whether numbers, letters ,or symbol, in binary form and they
work with numbers in the form of separate discrete digits .
 They can be used in different applications ( like commercial , administrative and
Mathematical ) since they can store different set of instructions and program .
 There are Three major elements in a digital computer which help in solving the
problems they are.
 Hardware
 Software
 Data
 Example Desktop PC , not books, work stations ,smart phones etc

7. Hybrid Computer
 The combination of features of analog and digital computer
is called Hybrid computer.
 These computers use analog to digital and digital to analog converters to convert the
analog signals into discrete numbers and digital numbers to analog signals
 Used in various areas of engineering,
 space vehicle simulation, passenger flight
radar system, also used to control robots.
 Example in hospital intensive care unite (ICU),a machine is used to monitor the blood pressure
and temperature of the patient .
 Digital thermometer and ECG machine are example of hybrid computer

8. On the basis of size and capacity
Super Computers
 They are very powerful and expensive and huge size computer
 They are used in complex scientific applications like geological data .
genetic engineering
 They are the fastest calculating device ever invented and are not used for
commercial data processing
 They have huge primary memory and the most advanced capabilities
 They support multiprocessing and parallel processing and allow thousand
of users to use it at the same time
 Their operating system is also very complex.

9. Mainframe Computers
 They are not as powerful as super computers but are extremely expensive.
 They are multi-programing , multi-user and high performance computer.
 They operate at a very high speed
 They have very large storage capacity and can handle the workload of many
users.
 The processing speed of mainframe computers is measured in MIPS(Million
Instructions Per second) i-e 200-1200 MIPS
 They are used in organizations where many people require frequent access to
same data like banks , insurances company , airlines etc

10. Mini computers
 Mini Computers are much smaller in size than mainframe computers.
 They are suitable for small business requirement of a server or host which
supports hundreds of users at a time .
 In business they are used for invoicing stock control payroll sales analysis
production planning etc
 Their speed of operations and memory space is lesser the mainframe computer
 Example mini computers IBM 8000 seriesm

11. Micro Computers
 Micro computers are small , low cost and single user digital computer.
 Microcomputers are stand alone computers but they can be connected
together using internet and wires to create a network of computers that
can serve more than one user .
 Desktop computers notebooks , laptops tablets smart phones