PIC Stands for:
Peripheral Interface Controller
Programmable Integrated Circuit
A PIC is a chip that can be programmed to do a number of different functions. They are used in electronic products such as: remote controls, microwave ovens, car remote key fobs, washing machines, and much more. It is a whole computer built into a single chip
A PIC can replace many other components in a circuit. Two security alarm circuits are show below - the first circuit uses standard components whereas the second circuit only uses a PIC they look totally different but yet can both perform exactly the same function!