A Motherboard (or System Board) is a one of the most essential parts of not just the computer, but many electronics such as televisions and stereos.
Also referred to as a Mobo, this component is in charge of relaying information between all the different components connected to it.
It's safe to say the microprocessor is the heart of the computer and the motherboard is the body and structure.
The system board itself is made up of chips, transistors, and circuits.
The different components, such as the video card, pci cards, and the memory modules talk to each other by transferring data and information along the circuits, or buses on the system board.
Pretty much all the internal components of a computer are connected to the system board.
Every motherboard operates off of a BIOS (Basic Input/Output System), which is basically a small program inside a chip on the board that controls how the motherboard operates and handles the components connected to it.
When you first turn your computer on, before your operating system loads up, you are seeing your BIOS in action.
All those gobbled up words running across the screen is your BIOS running its self tests to see what all is connected to the motherboard, and if there is any problems with any of the components.
When building your own computer, making sure the motherboard you choose has the correct socket for the processor you choose is crucial.
Most computer builders pick out a processor first and then choose a motherboard accordingly.
So I you were to pick out a Socket 478 Pentium 4 processor then you have to make sure you pick out a motherboard that will fit a Socket 478 Pentuem 4 processor.
It's also always a good idea to purchase a motherboard with more slots (pci and memory) than you currently need, so you can have room for expansion.