This document provides an overview of embedded systems, including definitions, common uses, typical hardware components, and microcontrollers. It defines an embedded system as a specialized computer system that is part of a larger device. Embedded systems are used widely in appliances, vehicles, phones, sensors, and more. Common hardware includes microcontrollers, microprocessors, DSPs and system-on-chip designs. The 8051 microcontroller family is discussed as a popular example.