What is a computer or Definition of a computer.

Consider this sentence: “Computers are everywhere. "Does it sound like an overstatement? A cliche? No matter how you perceive the impact of computers, the statement is true. Computers are everywhere. In fact, you can find them in some preny unlikely places, including your family car, your home appliances, and even your alarm clock! In the passage two decades, computers have reshaped our lives at home, work, and school.

The vast majority of businesses now use computerized equipment in some way, and most companies arc networked both internally and externally. More than half of all homes in the United States have at least one computer, and most of them are connected to the Internet. Workers who once had little use for technology now interact with computers almost every minute of the workday. 

This lesson examines the many types of computers that arc in common use today. Although this class w ill focus on personal computers (the ones that seem to sit on ever desktop), you will first learn about the wide variety of computers that people use, and the reasons they use them. As your knowledge of computers grows, you w ill understand that a ll computers regardless of their size or purpose are basically similar. That is, they all operate on the same fundamental principles, are made from the same basic components, and need instructions to make them run.


In basic terms, a computer is an electronic device that processes data, converting it into information that is useful to people. Any computer regardless of its type is controlled by programmed instructions, which give the machine a purpose and tell it what to do. The computers discussed in this article and which are everywhere around you are digital computers. As you will team in , “ Processing Data," digital computers are so called because they work “ by the numbers." That is, they break all types of information into tiny units, and use numbers to represent those pieces of information.

Digital computers also work in very strict sequences of steps, processing each unit of information individually, according to the highly organized instructions they must follow. A lesser-known type of computer is the analog computer; which works in a very different way from digital computers. 

The earliest computers were analog systems, and today's digital systems owe a great deal to their analog ancestors. Analog and digital computers differ in many respects, but the most important distinction is the way they represent data. 

Digital systems represent data as having one distinct value or another; with no other possibilities. Analog systems, however represent data as variable points along a continuous spectrum of values. This makes analog computers somewhat more flexible than digital ones, but not necessarily more precise or reliable. 

Early analog computers were mechanical devices, weighing several tons and using motors and gears to perform calculations. A more manageable type of analog computer is the old-fashioned slide rule. 

Computers can be categorized in several ways. For example, some computers are designed for use by one per- son, some arc meant to be used by groups of people, and some are not used by people at all. 

They also can be categorized by their power, which means the speed at which they operate and the types of tasks they can handle. Within a single category, computers may be sub-categorized by price, the types of hardware they contain, the kinds of software they can run, and so on.