computer summary computer , Programmable machine that can store, retrieve, and process data. Today’s computers have at least one CPU that performs most calculations and includes a control unit and an arithmetic logic unit. Main memory is an integral part of the computer but is separate from the CPU. Increasingly, personal computer s contain specialized graphic processors, with dedicated memory, for handling the computations needed to display complex graphics, such as for three-dimensional simulations and games. Auxiliary data storage is usually provided by an internal hard disk and may be supplemented by other media such as external hard disks, USB flash drives, or optical drives that use CD-ROMs or DVD-ROMs. Peripheral equipment includes input devices (e.g., keyboard, mouse) and output devices (e.g., monitor, printer), as well as the circuitry and cabling that connect all the components. Generations of computers are characterized by their technology. First-generation ...