The motherboard ties all the other parts of the computer together. It allows all the other parts to recieve power, work together, and communicate. The first IBM PC motherboard was just a processor and card slots and users could plug in floppy drive controllers and memory into the slots. However, today motherboards posses a wide list of built in features.
The motherboard holds the microprocessor chip of the computer and connects all the other parts to it. The socket for the microprocessor chip affects what kind of CPU the computer has. The form factor is the layout of the motherboard. The form factor has to do with where all the components get plugged into and it also determines the shape of the computer.
The chipset contributes to the motherboard's logic system and is made up of the north bridge and the south bridge. It's these two bridges that connect the CPU to the other parts of the computer. The Basic Input/Output system chip controls the most basic functions of the computer and some systems include a dual BIOS for backup in case one fails. The battery operated chip that controls the basic settings and system time is called the real time clock chip.
Some slots and ports found on the motherboard include the Peripheral Component Interconnect which provides connection for video, sound and video capture cards, as well as network cards. The Accelerated Graphics Port is a dedicated port for video cards and the Integrated Drive Electronics has interfaces for the hard drives. It also has the Universal Serial Bus or FireWire which have external peripherals and, last but not least, memory slots.