Computer is an advanced electronic device that takes raw data as input from the user and processes these data under the control of set of instructions (called program) and gives the result (output) and saves output for the future use.
It can process both numerical and non-numerical (arithmetic and logical) calculat.
A computer is a programmable device that can store, retrieve, and process data.
Computers differ based on their data processing abilities. They are classified according to purpose, data handling and functionality.
Personal computer: A small, single-user computer based on a microprocessor. In addition to the microprocessor, a personal computer has a keyboard for entering data, a monitor for displaying information, and a storage device for saving data.
Workstation : A powerful, single-user computer. A workstation is like a personal computer, but it has a more powerful microprocessor and a higher-quality monitor.
Minicomputer : A multi-user computer capable of supporting from 10 to hundreds of users simultaneously.
Mainframe : A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously.
Supercomputer : An extremely fast computer that can perform hundreds of millions of instructions per second.