Based on operating principles, computers can be classified into 3 types. They are,
1. Digital Computers
2. Analog computers
3. Hybrid computers
1. Digital computers:
They operate essentially by counting. All quantities are expressed as discrete digits or numbers. Digital computers are useful for evaluating arithmetic expressions and the manipulation of data. The majority of the computers used in the world today are digital.
2. Analog Computers:
They operate by measuring rather than counting. The computer functions by establishing similarities between two quantities that are usually expressed as voltages or currents. Analog computers are powerful tools to solve differential equations.
3. Hybrid Computers:
Computers which combine features of both analog and digital type are called hybrid computers. Computers are also classified in terms of speed, accuracy, word length and storage capacity. Computers are also available in different sizes and with different capabilities. Broadly, they may be categorised as microcomputers, mini, mainframe, and supercomputers.
1. Micro Computers:
Computers using Microprocessors are called Microcomputers. This is the smallest general-purpose processing system usually designed for use by a single person at a time.
2. Mini Computers:
These are medium-sized computers that are costlier and powerful than a microcomputer. An important distinction between a micro and a minicomputer is that a mini-computer is usually designed to serve multiple users simultaneously. This type of computers need less power and less cooling arrangements. Up to 8 users can use the system simultaneously, running their own individual programs.
3. Super Computers:
The supercomputer is the largest, fastest and most expensive mainframe computer. It is normally used by large business organisations that require an extraordinary amount of computing power. Their computing speed is 10 times faster than any other type of computer. These computers are capable of executing more than 10,000 million instructions per second and have storage capacities of millions of bits per chip.
Normally, the supercomputer is used for solving or handling large scale numerical problems in scientific and engineering fields. These include applications in electronics, petroleum engineering, weather forecasting, structural analysis, chemistry, medicine, and physics.
