Anyone who has lived in a modern society within the last few years is aware of what a computer is. We all have seen them, and we have all used them. Sometimes we are aware we are using a computer, and sometimes we are not. Even though we know what a computer looks like, and we might know something about what it does, there are some puzzling things about the nature of this machine that make understanding it a little more elusive than other machines. In this section, we will examine what actually happens deep inside the computer and see how it really works. You will discover an interesting paradox. Although computers are almost completely universal, capable of doing all kinds of complex processes, they can only really do a very select number of tasks. These simple tasks are combined in complex ways to make the computer capable of very complicated jobs. We are also used to seeing computers deal with every kind of information from words to numbers to pictures and music. We will see that computers can actually deal only with a very limited kind of information, but it can manipulate that information in very complex ways so it can be interpreted as text, music, or whatever.
We will define a computer in this way: A computer is a universal information manipulator. We will see in our discussions today exactly what that means.