kernel
n//ˈkərnəl//kärna, korn, operativsystemkärna, operativsystemskärna
The core, center, or essence of an object or system.
(botany) The central (usually edible) part of a nut, especially once the hard shell has been removed.
(botany) A single seed or grain, especially of corn or wheat.
(computing) The central part of many computer operating systems which manages the system's resources and the communication between hardware and software components.
(mathematics, algebra, loosely, of a morphism f between algebraic structures) The set of elements of the domain of f which are mapped to an identity element.