Computer Basics
Classification of Computers
Computers are classified based on size/capacity, Data processing/handling capabilities, Computer generations and the purpose
Based on Size or Capacity computers are classified as Supercomputers, Mainframes, Mini computers and Micro computers(PCs)
Supercomputer
• Supercomputer is a multiuser, most powerful and fastest computer
• It is expensive
• Mostly used by scientists and engineers
• Example: Fugaku supercomputer etc
Mainframe
• Mainframe is powerful than minicomputer
• It is a multiprocessing computer and processing is quite fast
• It is a multi-user computer
• It solves complex calculations and works for long periods of time
• It is used by large organizations
• Example: IBM zSeries mainframe computer, UNIVAC etc
Minicomputer
• It is a digital, multiprocessing and multi-user computer
• It is powerful than microcomputer
• Used in small business applications
• Example PDP-11 etc
Microcomputer (PC)
• It is a single-user computer
• It is a small computer and less expensive
• They can be desktop computers, laptops, smartphone, tablet or workstation (single-user computer connected to network)
• Used to process everyday tasks
Based on Data processing capabilities computers are classified as Analog computers, Digital computers or Hybrid computers
Analog computer
• It uses analog signals which are electrical, mechanical changes etc.
• It measures physical quantities like temperature and distance
• It is fast
• Accepts input in analogue form
• Used in scientific and engineering fields
• Example: Speedometer, Voltmeter etc
Digital computer
• Accepts input in digital form
• It is based on binary digits 0 and 1
• Performs calculations and logical operations
• It is slower than analog computers but more accurate and reliable
• Example: Laptops, desktops, smartphones, tablets etc
Hybrid computer
• It has both characteristics of the speed of analog computers and the accuracy of digital computers
• Solves complex problems quickly
• Example: Electrocardiogram(ECG), Ultrasound machine and fuel vending machine at gas station
Based on generations computers are classified into 5 generations
First generation computers are vacuum tube based and were in the years 1940s and 50s
Second generation computers are transistor and diode based and were in the years 1950s and 60s
Third generation computers are integrated circuit(IC) based and were in the years 1960s and 70s
Fourth generation computers are microprocessor based and were in the years 1970s to the present
Fifth generation computers are artificial intelligence(AI) based and were in the present and the future
Based on purpose computers are classified into general and special purposes
General purpose computers
• Used in everyday tasks like word processing
• Less expensive and limited capacity
• Example: Laptops, desktops, smartphones, tablets etc
Special purpose computers
• Used to perform a special task like weather forecasting
• More expensive and has higher capacity
• Example: ATMs and Washing machines etc