Classification of Computer
Based on Size
On the basis of size, computers are categorized as follows:
These are the least powerful, yet the most widely used and fastest growing type of computers and are also called portable computers.
Some types of micro computer are given below:
(i) Desktop Computer or Personal Computer (PC) These computers are small and relatively inexpensive computers. These computers are based on the microprocessor technology (Integrated Circuit).
(ii) Notebook These computers (also known as ultra book or laptop) are lightweight and fit into most briefcases. First laptop was developed by Alan Kay. Laptops consume less power than desktops and they include a rechargeable battery.
(iii) Handheld Computers or Palmtops These computer are the smallest and are designed to fit into the palm. So, these computers are also known as Palmtops.
(iv) Tablet Computer These computers have key features of the notebook computer, but it can accept input from a pen instead of the keyboard or mouse.
These computers are smaller in size and faster than mainframe computers. Initially, the mini-computers were designed to carry out some specific tasks, like engineering and Computer Aided Design (CAD) calculations. They are used as central computer, which is called a server.
These are the computers having large internal memory storage and comprehensive range of software. These computers are comparatively bigger in size than mini computers but smaller than supercomputers. Mainframe computer serves as a backbone for the entire business world. Mainframe computers are IBM-370, IBM-S/390, UNIVAC-1110.
These are the fastest and the most expensive machines. The speed of supercomputers are 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. “PARAM was the first supercomputer of India introduced by CDAC in 1991”.
Based on Work
On the basis of work, computers are categorized as follows:
An analog computer that uses the changeable aspect such as electric, mechanical quantities to solve the problem. These computers carry out arithmetic and logical operations by manipulating and processing data, e.g. speedometers, seismograph, etc.
This type of computers work by calculating the binary digits. A digital computer not only performs mathematical problems, but also combines the bytes to produce desired graphics, sounds, e.g. desktop (PC).
These computers are the combination of analog and digital computers. Machines used in hospitals like ECG and DIALYSIS are the commonly used hybrid computer. These computers contain special equipment to convert analog voltage to digital voltages and vice-versa.
Based on Purpose
On the basis of purpose, computers are categorized as follows:
General Purpose Computer
These computers are used to solve a variety of problems by changing the program or instructions, e.g. to make small database calculations, accounting, etc.
Special Purpose Computer
These computers are used to solve a single and dedicated type of problem, e.g. automatic aircraft landing, multimedia computer, etc.