Main difference between Microprocessor and microcontroller is

in microcontroller there is a memory but in microprocessor there is

no memory.

microprocessor:

        used for multiple applications.

microcontroller:

        used for pre-defined application.

Microprocessor is the central processing unit in a computer. To make it to work it will need lots of other ICs around it (like ROM, RAM and timers).

Microcontroller is like a computer inside a single chip. Typical microcontroller has all necessary parts (CPU, ROM, RAM, timers) integrated inside one IC.