A motherboard is the main printed circuit board in a computer. It holds many of the crucial electronic components that allow the computer to function, such as the central processing unit (CPU), random access memory (RAM), and input/output (I/O) ports. The motherboard also includes circuitry that allows the CPU to communicate with other devices in the system, such as hard drives, graphics cards, and optical drives.

Motherboards come in a variety of form factors, which dictate the size and shape of the board. The most common form factor for desktop computers is ATX, while Mini-ITX is popular for small form factor (SFF) systems. Motherboards also come in a variety of types, which determines what kind of processors they are compatible with. For example, there are motherboards designed specifically for AMD or Intel processors.