Motherboard

Definition - What does Motherboard mean?

A motherboard is a computer’s main circuit board, and it includes the following attached to a fixed planar surface:

Input/output ports
Peripheral connections
PCI expansion slots
Bus and power connectors
Heat sinks and mounting points for fans and major components, including the central processing unit (CPU) and optional coprocessors
Supporting chipset for CPU, bus and external components
BIOS
Memory sockets for RAM, ROM and cache
Interconnecting circuitry

Additionally, daughterboards and mezzanine cards, installed on a second level, may be plugged into the motherboard. A daughterboard may be the actual motherboard and/or card or board plugged into the motherboard.

The motherboard is also referred to as the main board (mobo), system board or planar board. Apple computers refer to the motherboard as the logic board.

Techopedia explains Motherboard

The Advanced Technology (AT) motherboard is the most common and is based on the IBM AT motherboard - a design improved with the Advanced Technology Extended (ATX) specification.

Components such as external storage, video display, sound controllers and peripheral devices may be attached to the motherboard. However, these components are increasingly integrated into the motherboard. For example, disk controllers, graphics controllers supporting 2D/3D graphics and TV input, sound card output, fast Ethernet network controller, USB 2.0 controller (with up to 12 USB ports), an infrared data communication IrDA controller (for mobile phones and printers) and temperature, voltage, and fan-speed sensors all may be contained within the motherboard.