The document discusses the history and applications of microprocessors. It begins with an informal definition of a microprocessor as the "brain" of a computer contained on a single chip. It then discusses how microprocessors can be found in general purpose computers, embedded systems, and special purpose devices. The history section outlines some of the earliest and most advanced microprocessors developed by Intel, from the 4004 in 1971 to the Pentium 4 in the early 2000s, showing the rapid increase in capabilities. The document concludes by discussing the basic components and architecture of microprocessor systems.