Core

The innermost layer of the Sun, where energy is released by the fusing together of nuclei to form heavier nuclei (nuclear fusion).

The innermost part of the Sun. The core produces colossal amounts of energy, including all of the Sun's light and heat. The temperature and pressure are so great in the Sun’s core that hydrogen atoms are squeezed together to form helium. This reaction is called nuclear fusion. The temperature at the center of the Sun is about 15,000,000 °C (27,000,000 °F) and the density is about 10 times that of gold or lead.

(Kor) the central part of anything, such as the central mass of necrotic matter in a boil.

A short form for "core file." The file that contains the contents of a core dump.

The central region about the longitudinal axis of an optical fiber, which region supports guiding of the optical signal. Note 1: For the fiber to guide the optical signal, the refractive index of the core must be slightly higher than that of the cladding. Note 2: In different types of fibers, the core and core-cladding boundary function slightly differently in guiding the signal. Especially in single-mode fibers, a significant fraction of the energy in the bound mode travels in the cladding. 2. A piece of ferromagnetic material, usually toroidal in shape, used as a component in a computer memory device. Note: The type of memory referred to has very limited application in today's computer environment. It has been largely replaced by semiconductor and other technologies. 3. The material at the center of an electromechanical relay or solenoid, about which the coil is wound.