We generally associate the term computer with laptops, desktop computers, or even mobile devices. This is only a very small sample of computers, however. Most computers exist as part of other systems (say mechanical or electronic systems), and they range from simple coffee makers to incredibly complex aircraft navigation systems. These computers are referred to as embedded, and are different in that they are dedicated special purpose devices. Unlike general-purpose computers, embedded ones tend to serve a single purpose throughout their lifetime. Consider an everyday printer. While it is possible to replace printer software with software of a different type, only more printer software would make sense. Embedded computers can be built from either microprocessors or micro-controllers. Let us look explore the differences.