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
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. But theoretically, anything one computer is capable of doing, another will also be able to do. Given the right instructions, and sufficient memory, a computer found in a wristwatch should be able to accomplish anything a supercomputer can although it might take thousands of years for the wristwatch to complete the operation.