Also known as: Mainboard, Logic board

A motherboard (or mainboard) is the main printed circuit board of a computer — the backbone that holds the CPU, memory, and chipset and wires every other part together.¹

Overview

The board provides a socket for the CPU, slots for RAM, and connectors and expansion buses such as PCIe, USB, and SATA. Its chipset and traces route signals between the processor, memory, storage, and I/O. Firmware (BIOS/UEFI) lives in a chip on the board and brings the system up at power-on. Physical size and mounting follow a form factor — common ones are ATX, microATX, and Mini-ITX.

Where it fits

Everything plugs into the motherboard, so it sets what a machine can hold: how many memory channels, how many PCIe lanes, which CPU generation. Power arrives from the PSU through dedicated connectors. A small-form-factor board — like the one inside a Raspberry Pi acting as a GopherTrunk capture node — folds the chipset and I/O onto a single tiny PCB, but the role is the same: be the board that everything else connects to.

Sources

1. Motherboard — Wikipedia, on the main board of a computer and what it carries. ↩

See also

• Central processing unit (CPU)
• Chipset
• PCI Express (PCIe)
• System bus
• Power supply unit (PSU)
• Integrated circuit