Classification of Computer | How are Computer's Classified | Computer Basics

Computers are mainly classified into three types as follows

Based on Size 

On the basis of size, computers are categorized as follows

• Microcomputer: These types of computers are the least powerful, yet the most widely used and are also called portable computers. Microcomputer consists of three basic categories of physical equipment, i.e. system unit, input/output unit, and memory unit. Some types of microcomputers are as follows 

1. Desktop Computer or Personal Computer (PC): These are small, relatively economical computers. These are based on microprocessor technology (Integrated Circuit-IC).
2.  Laptop: These computers are also known as ultrabooks or notebooks. These are portable and lightweight. They include a rechargeable battery, so these can work anywhere. 
3. Handheld or Palmtop Computer: These are the smallest and are designed to fit into the palm. So, these are also known as Palmtop. They are practical for certain functions such as phone books and calendars. They use the pen for input instead of a keyboard. e.g. PDA (Personal Digital Assistant), tablets, etc. 
4. Tablet Computer: They have key features of the notebook computer, but these can accept input from a pen instead of the keyboard or mouse. 
5. Workstation Computers: These are computers dedicated to a user or group of users engaged in business or professional work. It includes one or more high-resolution displays and a faster processor than a Personal Computer (PC).

• Minicomputers: These are smaller in size, faster, and cost lower than mainframe computers. Initially, the minicomputer was designed to carry out some specific tasks, like engineering and Computer Aided Design (CAD) calculations. But now, they are being used as a central computer which is known as Server. Minicomputers are IBM-17, DEC PDP-11, HP-9000, etc. 

• Mainframe: Computer These types of computers have large internal memory storage and a comprehensive range of software. Mainframe computer serves as a backbone for the entire business world. It is considered the heart of a network of computers or terminals that allow a large number of people to work at the same time. Mainframe computers are IBM-370, IBM-S/390, UNIVAC-1110, etc.

• Supercomputers: These are the fastest and most expensive machines. They have a high processing speed compared to other computers. Supercomputers are most powerful, large in size and memory, compared to all other computers. The speed of supercomputers is measured in FLOPS (Floating Point Operations Per Second). Supercomputers are used for highly calculation-intensive tasks, such as weather forecasting, nuclear research, military agencies, and scientific research laboratories. 

1. CRAY-1 was the world’s first supercomputer introduced by Seymour R CRAY in 1976. 
2. PARAM was the first supercomputer developed in India in 1990. 
3. PARAM ISHAN is the latest machine in the series of PARAM made by C-DAC and IIT Guwahati on 20th September, 2016.

Based on Work 

On the basis of work, computers are categorized as follows 

• Analog Computer: These computers carry out arithmetic and logical operations by manipulating and processing data. e.g. Speedometers, seismographs, etc. Analog computers can perform several mathematical operations simultaneously. It uses continuous variables for mathematical operations and utilizes mechanical or electrical energy. 

• Digital Computer: These do work by calculating the binary digits. A digital computer, not only performs mathematical calculations but also combines the bytes to produce desired graphics and sounds. e.g. Desktop (PC). 

• Hybrid Computers: These are the combination of analog and digital computers. Machines used in hospitals like ECG and DIALYSIS are the commonly used hybrid computers. 

Based on Purpose 

On the basis of purpose, computers are categorized as follows 

• General Purpose: Computer General purpose computers are those computers, which are used to solve a variety of problems by changing the program or instructions. e.g. To make small databases, calculations, accounting, etc.

• Special Purpose Computer Special purpose computers are those computers that are used to solve a single and dedicated type of problem. e.g. Automatic aircraft landing, multimedia computer, etc.

Quantum computer was first introduced by Richard Feynman. It uses quantum mechanical phenomena. It is the fastest computer imitating brain working. 

Nano computer is a general team used to describe a computer smaller than a microcomputer, usually about the size of a credit card. e.g. Raspberry Pi which could be used in schools to teach science to children. 

Pratyush India’s fastest and first multi-petaflops (PF) supercomputer named Pratyush was unveiled at Punebased Indian Institute of Tropical Meteorology (IITM). Pratyush has 6.8 PF computational power installed at two MoES Institutes. 4.0 Peta Flops HPC facility at IITM, Pune and 2.8 Peta Flops facility at NCMRWF, Noida. Pratyush is fourth fastest supercomputer in the world dedicated for weather and climate research. 

Note PF is a measure of a computer’s processing speed.