The document provides an introduction to embedded systems. It defines an embedded system as a microprocessor-based system designed to perform dedicated functions, often as part of a larger system. Embedded systems are found in various applications ranging from home appliances to medical devices to industrial systems. The document discusses why microcontrollers are commonly used in embedded systems due to their integrated memory and I/O peripherals. It also outlines the typical hardware and software architecture of an embedded system and classifications including stand-alone, real-time, and networked systems.