This little chip is the heart of a computer. Often referred to as just the "processor," the microprocessor does all the computations like adding, subtracting, multiplying, and dividing. In PCs, the most popular microprocessor used is the Intel Pentium chip, whereas Macintosh computers use the PowerPC chip (developed by Motorola, IBM, and Apple).

The speed of a microprocessor is measured in megahertz, or cycles per second. But higher megahertz doesn't always mean better performance.

The first microprocessors emerged in the early 1970s and were used for electronic calculators, using BCD arithmetic on 4-bit words. Other embedded uses of 4 and 8-bit microprocessors, such as terminals, printers, various kinds of automation etc, followed rather quickly.