The Mainboard/Motherboard is the central nervous system of a computer. All data, processes, and operations that are performed, pass through the mainboard. In an a home desktop, it acts as the board in which all other components found in the computer connect to. All desktop PC's will contain the Mainboard, where a Central Processing Unit(i.e. Pentium III 500), RAM, a Hard drive, and Video Card are attached. Other multimedia, and communication devices such as modems, network cards and sound cards can be added via slot expansions on the mainboard.