An embedded system is a specialized computer system that is part of a larger system or machine. Embedded systems can also be thought of as information processing subsystems integrated in a larger system. As part of a larger system it largely determines its functionality. An embedded system usually contains an embedded processor. Many appliances that have a digital interface&#151microwaves, VCRs, cars&#151utilize embedded systems. Some embedded systems include an operating system. Others are very specialized resulting in the entire logic being implemented as a single program. These systems are embedded into some device for some specific purpose other than to provide general purpose computing.