The personal computer (abbreviated PC) is a computer that does not need to be connected to a larger computer in order to operate, and is capable of repetitively and efficiently performing calculations and instructions while being operated by an individual. It is smaller, less expensive, and easier to use than other types of computers such as minicomputers, mainframes, and supercomputers. The PC traces its ancestry to the mainframes and minicomputers of the 1950s and 1960s, which were all based on microprocessor technology that enabled manufacturers to place an entire central processing unit (CPU) on one semiconductor chip in order to perform all arithmetic, logic, and control functions.

In the 1960s, when microcomputers (they were not yet called personal computers) were evolving, they were distinguished from other computers by their size--they were smaller than minicomputers, which in turn were smaller than mainframes. While early mainframes needed the...