What is a Motherboard?

The motherboard is the most essential component in a personal computer . it is the piece of hardware which contains the computer's micro-processing chip and everything attached to it is vital to making the computer run.

Motherboard Components

If you open your computer's case, the motherboard is the flat, rectangular piece of circuit board to which everything seems to connect to for one reason or another. It contains the following key components:

A microprocessor "socket" which defines what kind of central processing unit the motherboard uses;
A chipset which forms the computer's logic system. It is usually composed of two parts called bridges (a "north" bridge and its opposite, "south" bridge), which connects the CPU to the rest of the system;
A Basic Input/Output System (BIOS) chip which controls the most basic function of a computer, and how to repair it; and
A real-time clock which is a battery-operated chip which maintains the system's time, and other basic functions.

The motherboard also has slots or ports for the attachment of various peripherals or support system/hardware. There is an Accelerated Graphics Port, which is used exclusively for video cards; Integrated Drive Electronics, which provides the interfaces for the hard disk drives; Memory or RAM cards; and Peripheral Component Interconnect (PCI), which provides electronic connections for video capture cards and network cards, among others.

How a Motherboard Works

The most important thing to remember about the motherboard is that it is a printed circuit board which provides all the connections, pathways and "lines" connecting the different components of the computer to each other - specifically, the Central Processing Unit or CPU, which is where (as its name implies) all the "processing" is going on to everything else.

The CPU or "chip" (the most popular of which is Intel's Pentium series) is an assembly of transistors and other devices (Pentium IV has over 4 million transistors) which perform or processes myriad programmed tasks.

The CPU rests in a "socket" on the motherboard which is connected to the other components through the board's printed circuits. The most important connections are to the chipsets - especially the northbridge chipset which is connected to the main computer memory (hard disk and RAM), while the southbridge set is connected to the peripherals - video and audio cards, IDE controllers, etc.

Aside from these, the most important element of the motherboard is the BIOS chip - which performs key functions like checking power supply, the hard disk drive, operating system, etc. before the computer actually starts "booting up". Turning on the computer automatically starts the BIOS chip up to perform its diagnostic functions, after which it powers up the CPU which - in its turn - starts powering up the other peripherals (hard disk, operating system, video and audio, etc.).

This is why the motherboard is the key component of the computer. It is, in effect, the "housing" for the CPU - the place where the latter resides and from which commands, instructions, and power course through before being sent out to other components.