Microprocessors act as the brains of computers.
Unlike personal computers, however, the presence of an embedded system or chip is far from obvious, and may be impossible to discover by casual observation. Embedded chips are used in thousands of applications as part of control and monitoring systems. For example, embedded chips can be found in talking greeting cards, telephones, cellular phones, copiers, scanners, printers, bar code readers, video cassette recorders, televisions, cameras, cash registers, automobiles, traffic management systems, HVAC systems, elevators, power management systems, security systems, assorted medical devices such as defibrillators and medication delivery systems, and in many factory production machines and systems. The most simple embedded systems are capable of performing only a single function or a set of functions to meet a single predetermined purpose. The functionality of more complex embedded systems can be driven by the engine of a computer program.