Along with the CPU the motherboard is probably the most important componant in a personal computers. Every other device such as hard disks, cd-roms, memory, CPU's, floppy drives is connected to and runs off the motherboard. The motherboard dictates the speed of all devices and is the circuit board which the power supply runs through. A motherboard includes a variety of slots such as AGP, PCI, AMR, parallel ports, ps/2 interface, on-board IDE, memory sockets and much more.