motherboard

The main printed circuit board in a complex electronic device, such as a personal computer, usually containing the central processing unit, the main system memory, and other components essential to the device’s operation.

The board containing the main circuits of an electronic device, especially computers. The term is used primarily in microcomputer literature, where it designates the board containing the main expansion bus, and usually also the cpu. On motherboards designed with an expansion bus, often all of the circuits not contained on an expansion card are on the motherboard.

the primary circuit board of a personal computer, containing the circuitry for the central processing unit, keyboard, mouse and monitor, together with slots for other devices

the main circuit board for a computer