The Definition of a motherboard
The motherboard is the primary printed circuit board in a PC. All of the basic circuitry and components required for a PC to function are either contained in or attached to the motherboard. The motherboard typically contains the system bus, processor, memory slots, serial and parallel ports, expansion slots, and peripheral controllers. The motherboard may be alternatively referred to as the mainboard, system board, or even maincard or mothercard, but regardless of what you call it, it is the central component that enables all of the other parts of a computer to work and match.