Microprocessor, integrated circuit that performs the functions of a large computer on a tiny “chip” of silicon. Unlike a computer, which can be programmed to solve many different problems, a microprocessor is designed for a specific task. Microprocessors are called very large-scale integrated circuits because they may contain more than 100,000 transistors. First produced in 1971, microprocessors today can perform about 66 million functions per second. Microprocessors are used in a variety of “smart” devices, including appliances used at home, businesses, and industrial plants.