Core

Core generally is the heart or inner part of a thing, as of a column, wall, rope, of a boil, etc.; especially, the central part of fruit, containing the kernels or seeds; as, the core of an apple or quince.

Core could mean:

In media:
 Core (album), an album by Stone Temple Pilots
 Core (Persefone album)
 Core (radio station), a digital radio station in the United Kingdom
 The Core, a 2003 science fiction film
 Core Design, a videogame developer best known for the Tomb Raider series
 C.O.R.E., a computer animation studio

In science and academics:
 Core (group), in mathematics, an object in group theory
 Core (functional analysis), in mathematics, a subset of the domain of a closable operator
 core (graph theory), in mathematics, the homomorphically minimal subgraph of a graph
 core of a triangulated category in mathematics. 
 Core (economics), the collection of stable allocations that no coalition can improve upon
 Planetary core, in planetary science, the center of a planet
 Earth's core
 Solar core, the region of the Sun where nuclear fusion takes place
 Lithic core, in archaeology, a stone artifact left over from toolmaking
 Core curriculum, in education, an essential part of the curriculum
 Core sample, in Earth science, a sample obtained by coring
 Core countries, in dependency theory, an industrialized country on which peripheral countries depend
 Core (anatomy), in anatomy is everything except the appendages.

In computers and technology:
Semiconductor intellectual property core, part of a CPU design
Multi-core (computing), a type of microprocessor design in which multiple processors coexist on the same chip
 Intel Core, in processors, a brand of computer processor
 Magnetic core memory, in computing, the primary memory
 Core dump, in computing, a record of the core memory
 Nuclear reactor core, a portion containing the fuel components
 Magnetic core, in electricity and electronics, ferromagnetic material around which wires are wound
 the signal-carrying portion of an optical fiber

Acronyms:
 Central Organization For Railway Electrification, an organization in India
 Congress of Racial Equality, United States civil rights organization 
 Coordinated Online Register of Electors, central database in the United Kingdom
 Challenge of Reverse Engineering, a warez group
 Comment on Reproductive Ethics, a Christian pressure group in the United Kingdom