core

Core (kō`rē), variant of Korah.

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core

In earth science, the part of the Earth that starts about 1,800 mi (2,900 km) beneath the surface and extends downward. It consists largely of an iron-rich metallic alloy and is thought to have a two-part structure: an outer fluid region and a solid, extremely dense inner region that measures only about 1,500 mi (2,400 km) across. The alloy composition is mainly iron with small amounts of nickel. This composition is deduced from the chemistry of iron meteorites that presumably came from the breakup of a planetary body that also had an iron core. See also crust; mantle.

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(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.

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core - 1. Main memory or RAM. This term dates from the days of ferrite core memory; now archaic most places outside IBM, but also still used in the Unix community and by old-time hackers or those who would sound like them. Some derived idioms are quite current; "in core", for example, means "in memory" (paged in, as opposed to "on disk", paged out), and both core dump and the "core image" or "core file" produced by one are terms in favour. Some varieties of Commonwealth hackish prefer store.