A microcontroller is a specialized form of microprocessor that is designed to be self-sufficient and cost-effective, where a microprocessor is typically designed to be general purpose (the kind used in a PC). Microcontrollers are frequently found in automobiles, office machines, toys, and appliances.
The microcontroller is the integration of a number of useful functions into a single IC package. These functions are:
The ability to execute a stored set of instructions to carry out user defined tasks.
The ability to be able to access external memory chips to both read and write data from and to the memory.
Basically, a microcontroller is a device which integrates a number of the components of a microprocessor system onto a single microchip.
So a microcontroller combines onto the same microchip :
The CPU core (microprocessor)
Memory (both ROM and RAM)
Some parallel digital I/O
Also, a microcontroller is part of an embedded system, which is essentially the whole circuit board.
The difference is that microcontroller incorporates features of microprocessor(CPU,ALU,Registers)along with the presence of added features like presence of RAM,ROM,I\O ports,counter etc.Here microcontroller control the operation of machine using fixed programme stored in Rom that doesn't change with lifetime.
