Most of the microprocessors in the world are not in pcs, they are embedded in devices which control traffic for highways, airspace, railway tracks, and shipping lanes to manufacturing systems with robots. An embedded system is any device controlled by instructions stored on a chip. These devices are usually controlled by a microprocessor that executes the instructions stored on a read only memory (ROM) chip. Embedded systems can be used to implement features ranging from the way pacemakers operate and mobile phone that can be worn as jewellery to adaptive cruise control(ACC). In this section explain one such technology that uses the embedded systems- The Adaptive Cruise Control.