This document provides an overview of microprocessor systems and embedded devices at different levels. It discusses that at the high end, Intel Pentium 4 processors operate at 3.2GHz and consume over 100W, while low-power embedded devices consume as little as 250-300mW. Computer technology is experiencing dramatic changes with processors doubling in speed every 1.5 years, and memory and storage capacities increasing exponentially. Future computers are predicted to have processors operating at 5GHz with 4GB of memory and 2TB of storage. Embedded systems face challenges in power consumption, size, cost, reliability and meeting application-specific requirements.