A Microprocessor is a small sized and inexpensive computer. However another implication of this word is the heart of the microcomputer is a microprocessor. In fact, both these connotations are true in today's microcomputer scene.
Microcomputer is a device which must be capable of.
Receiving input(data and instructions).
Performing computations(arithmetic and logic).
Storing data and instructions.
Displaying the results of any computations, and.
Controlling all the devices that perform the above mentioned four tasks(directly or indirectly)
A device which enables a microcomputer to perform the first of the above tasks, is known as input device. Typical input devices used are keyboards, mouse and toggle switches. A device that performs that second of the above mentioned tasks is known as an Arithmetic logic unit(ALU). In microcomputers, this task together with control is performed by a microprocessor.
Storage of data and instructions is accomplished using memories. Several type of memories are in use. Semiconductor memories, which are relatively fast, are the most commonly used ones. Cassettes, floppy disks and hard disks are used together with semiconductor memories in relatively large microcomputer.
Microprocessor is a very imp subject in terms of its use. We all use the computers and they all are useless without the microprocessors. If there were no microprocessors we wont be able to access the information this fast we might be still in the ENIAC era where VACUUM TUBES were used or in the time of the transistors.