Another name for a motherboard.

The primary circuit board inside a PC.  The CPU, memory and all expansion peripherals plug into the mainboard.  Also called a Systemboard or Motherboard.

The mainboard, commonly called the mother board, is the central board of the computer, where all the main connection ports are mounted. It houses the buses between the main components. On the mainboard, there are usually controllers for parallel ports, serial ports, PS/2 port, floppy drives and hard drives. This is part of the hardware. See inside the case.

a complicated bit of work