What is a computer?

As commonly defined, a computer is a machine that electronically processes information according to a set of instructions called a program. You may have a computer in your watch, your microwave oven, your car, or your cell phone as well as on your desk. Today's computer is a miniaturized marvel, a mass of electronics packed onto a tiny wafer of silicon called a chip.

When most people picture a computer, they are actually thinking of a computer system – the computer plus all of the components that permit people to interact with the computer. Let's begin by taking a look at the hardware, the physical components, of a typical personal computer system.