Card

Card, in computer science, a term commonly used in reference to a printed circuit board or adapter that can be plugged into a computer to provide added functionality or new capability. Such cards provide specialized services, such as mouse support and modem capabilities, that are not built into the computer.

In programs such as the HyperCard hypertext program, an on-screen representation of an index card on which information can be stored and “filed” for future reference. See also Hypertext.

Historically, an 80-column manila card (also called a punched card) about 3 inches high by 7 inches long, on which 80 columns of data could be entered in the form of holes punched with a keypunch machine. The punched holes corresponded to numbers, letters, and other characters and could be read by a computer that used a punched-card reader.