Introduction
Computers are classified into three main groups. On the basis of data handling abilities analog computer, digital computer, hybrid computer. On the basis of size supercomputer, mainframe computer, mini-frame or minicomputer, microcomputer. On the basis of purpose general purpose, and special purpose.
Analogue Computer
Analogue computers are used to process analogue data. Analogue data changes continuously and don't have discrete values. Examples for analogue data are speed, temperature, pressure and current. It performs real-time operations and computation at the same time and continuous representation of all data within the range of the analogue machine.
Examples of analogue computers are thermometer, speedometer, analogue clock, seismometer, voltmeter, flight simulators, tide predictors.
Digital Computer
Digital computer are used to perform calculations and logical operations at high speed. It accepts input in the form of numerical digits or binary digits and processes it to produce the output.
Examples of digital computers are laptops, desktops, smartphones.
Hybrid Computer
Hybrid computer combines both features of analogue and digital computer. It is fast as analogue computer and has memory and accuracy of digital computers. It can process both continuous and discrete data. It accepts analogue signals and convert them into digital form before processing.
Examples of hybrid computers are gasoline station, electrocardiogram machine, ultrasound machine, monitoring machine, forensic, defence.
Supercomputer
Supercomputer gives a high level performance compared to a other computer. Its performance is measured in terms of floating-point operations per second (FLOPS) instead of million instructions per second (MIPS). Fugaku is the current fastest supercomputer, its computing speed 442 petaflops. Supercomputers are used for computational science, quantum mechanics, weather forecasting, climate research, oil and gas exploration, molecular modeling, physical simulations, and cryptanalysis.
Examples of supercomputers are Fugaku, Summit, Sierra, Selene, PARAM, Tianhe-2A etc.
Mainframe Computer
Mainframe computer are used by organizations for bulk data processing for tasks such as censuses, industry and consumer statistics, and large-scale transaction processing. It is large but not as large as a supercomputer. Mainframe computers are also used as servers.
Examples of mainframe computers IBM z15, UNIVAC series, HPE NonStop etc.
Minicomputer
Minicomputer is a mid-size computer, it lies between the mainframe computer and microcomputer. It consists of two or more processors and can support 4 to 200 users at a time. They are used in institutes and departments to keep track of billing, accounting and inventory management.
Examples of minicomputers CDC series, DEC PDP series, Data General Nova, HP 3000 series and HP 2100 series, K-202, Nord-10, and Nord-100 etc.
Microcomputer
Microcomputers are general-purpose computer and it is sometimes referred as personal computer. It is designed for individual use and are much suited for personal work.
Examples of digital computers are laptops, desktops, smartphones etc.
General-Purpose Computer
A general-purpose computers are used to perform most common computing tasks. Personal computers like desktops, notebooks, smartphones and tablets, are all examples of general-purpose computers.
Special-Purpose Computers
A special-purpose computers are used to perform task-specific computation and they are good at solving one particular problem. Traffic lights control systems, aircraft navigation systems, weather forecasting, satellite launch, and in automotive industries are the few examples of special-purpose computers.