Properties:

A round, flat item which is used as a storage media for programs required by a computer for solving specific problems or for information to be evaluated and displayed by a computer. The item may have a magnetic coating and be stored in a paper/plastic envelope. It may also be designed as an optical storage media (cd-rom) with pits on a reflecting surface that are sensed by means of an optical device or a laser beam. For items without programs or information see disk, flexible. See also tape program, automatic data processing. For items having no prerecorded data, see disk, flexible and tape, electronic data processing.