Computer technology is the application of computers to store, retrieve, transmit, and manipulate data, or information. Computer technology is used in a variety of fields, including computer science, software engineering, hardware engineering, mathematics, and statistics. It has been used extensively in the field of medicine since the early 1970s.
Computers can be classified by size and power as well as by the type of data they process. The first computers were called mainframes because they housed all the components necessary for computation in one large piece of equipment. Today’s personal computers (PCs) are more likely to be found on desktops or laptops than in large data centers. Mainframes and PCs are both examples of what is known as general-purpose computing devices; that is, they can be programmed to carry out a wide range of tasks. In contrast, some computers are designed for specific purposes; these are called special-purpose devices. For example, a supercomputer might be built for scientific or engineering applications that require very high levels of performance; conversely, a microcomputer might be designed for low cost and portability so that it can be used in consumer electronics applications such as digital watches or handheld calculators.