Microcontroller
A Microcontroller is a microprocessor optimised to be used to control electronic equipment.
Microcontrollers are used almost anywhere nowadays (eg washing machines, microwave ovens, telephones etc). In general the term 'Microcontroller' is applied to microprocessors designed for generic controller usage rather than custom processors.
A Microcontroller differs from a normal CPU because it generally is quite easy to make into a working computer, with a minimum of external support chips. For instance, a typical microcontroller will have a built in clock generator and a small amount of RAM and ROM/EPROM/EEPROM, meaning that to make it work, all that is needed is some control software and a timing crystal. Microcontrollers will also usually have a variety of I/O devices, such as Analog to Digital Convertors, timers, and simple digital I/O ports which can be controlled by specialised processor instructions.
Common Microcontrollers in use are