What is computer:

A computer is a device that accepts information (in the form of digitalized data) and manipulates it for some result based on a program or sequence of instructions on how the data is to be processed.

A computer generally means a programmable machine. The two principal characteristics of a computer are: it responds to a specific set of instructions in a well-defined manner and it can execute a prerecorded list of instructions (a program).

Modern Computers Defined

Modern computers are electronic and digital. The actual machinery — wires, transistors, and circuits — is called hardware; the instructions and data are called software.

 

Lets we briefly described the each portion:
How its works
Inventions
History
And much more...