Also called the "system board," it is the main printed circuit board in an electronic device, which contains sockets that accept additional boards. In a desktop computer, the motherboard contains the CPU, chipset, PCI bus slots, AGP slot, memory sockets and controller circuits for the keyboard, mouse, disks and printer. It may also have built-in controllers for modem, sound, display and network, obviating the need to plug in a card. A laptop motherboard typically has all peripheral controllers built in. See CPU, chipset, PCI, AGP and controller.