What is a Computer?

 

                   We are all familiar with what a computer is in a specific, contemporary sense. Personal computers are found in most aspects of daily life, and for some it is hard to even imagine a world without them. But the term computer means more than simply the Macs and PCs we are familiar with. A computer is, at its most basic, a machine which can take instructions, and perform computations based on those instructions.

              It is the ability to take instructions - often known as programs in the parlance of computers - and execute them, that distinguishes a computer from a mechanical calculator. While both are able to make computations, a calculator responds simply to immediate input. In fact, most modern calculators are actually computers, with a number of pre-installed programs to help aid in complex tasks.

        Computers range from the very small to the very large. Some are capable of doing millions of calculations in a single second, while others may take long periods of time to do even the most simple calculations.

           As prevalent as personal computers are, they do not nearly begin to scratch the surface of computer use in our world. Interactive devices of all sorts contain their own computers. Cellular telephones, GPS units, portable organizers, ATM machines, gas pumps, and millions of other devices all make use of computers to streamline their operations, and to offer features which would be impossible without a computer.

             A computer like this is often referred to as an embedded computer. An embedded computer is differentiated from a personal computer because it is essentially static in its function. While a personal computer, or some cellular telephones, or some personal organizers are able to have new software installed, and make use of a wide range of features, an embedded computer usually has only a few purposes, which are relatively fixed once the computer is manufactured.

                Embedded systems vary in the amount of change that can happen to them after production. An MP3 player, for example, is an embedded computer, but can have quite a bit of interaction and changes made to it. It may allow the user to alter the colors used, change the clock, update firmware, and change the songs or playlists in memory. An embedded computer within a traffic light, to take another example, is probably quite fixed. It is set to respond to a few certain programs - time of day, a trigger when a car approaches, and perhaps input from a central database in the case of more advanced systems. These programs are not built for interactivity, and will likely never be changed over the system's life.

               The computer is one of the most powerful innovations in human history. With the use of computers, people are suddenly able to perform a staggering amount of computations at dazzling speeds.