(1) The heart, or central part, of something. The core of a network is its backbone. A core program would be the primary routines that serve the entire application (see kernel).

(2) In digital electronics, it typically refers to a relatively large, general-purpose logic function that is used as a building block in a chip design. Examples are microprocessor, microcontroller and DSP cores. Cores may be developed internally, but are generally purchased from third-party intellectual property (IP) vendors. See soft core and hard core.

(3) A CPU. A microprocessor with two cores (dual cores) is a single chip that contains two processors. See dual core and multicore.

(4) (Core) A family of CPU chips from Intel. Introduced in 2006, the Core line was developed to supersede the Pentium brand. See Intel Core.

(5) A round magnetic doughnut that represents one bit in an earlier core storage system. When core storage was common in the 1960s, a computer's main memory used to be called "core." See core storage.