Today's motherboards typically boast a huge variety of built-in features, and motherboards directly affect a computer's capabilities, potential for upgrades. The motherboard is the "heart" of your PC which handles system resources, as well as core components, the CPU, and all system memories. It accepts expansion devices like sound and network cards, and modems. Also contains the connectors for connecting additional boards. Typically, the motherboard has the CPU, BIOS, memory, mass storage interfaces, serial and parallel ports, expansion ports, and all the controllers that is required for the control of standard peripheral devices, such as the monitor, keyboard, and disk drive. Collectively, these chips that reside on the main board (motherboard) are known as the motherboard's chipset and at which by itself it is useless.
 

    In the motherboards there are I/O ports which stand for Input and Output, with three different kinds PCI (Peripheral Component Interconnect ), ISA, and AGP (Accelerated Graphics Port) . In theses port you are able to put graphic cards, buses, and the CPU. Buses are a collection of wires through which data is transmitted from one part of a computer to another. You can think of a bus as a highway on which data travels within a computer. When used in reference to personal computers, the term bus usually refers to internal bus. The bus connects all the internal computer components to the CPU and main memory. An expansion bus that enables expansion boards to access the CPU and memory.

Organization

In one way or another, you are going to connect many components to your motherboard. The way the motherboards design and laid out, dictates how the entire computer is going to be organized.

Control

 The chipset and BIOS program control most of the data flow within the computer.

Communication

 Almost all communication between the computer and its peripherals, other PCs, and the user, goes through the motherboard.

Processor Support

The motherboard dictates directly your choice of processor for use in the system.

Peripheral Support

 The motherboard determines, in large part, what types of peripherals you can use in your PC. For example, the type of video card your system will use (ISA, VLB, PCI) is dependent on what system buses your motherboard uses.

Performance

The motherboard is a major determining factor in your system's performance, for two main reasons. First and foremost, the motherboard determines what types of processors, memory, system buses, and hard disk interface speed your system can have, and these components dictate directly your system's performance. Second, the quality of the motherboard circuitry and chipset themselves have an impact on performance.

Upgradeability

 The capabilities of your motherboard dictate to what extent you will be able to upgrade your machine. For example, there are some motherboards that will accept regular Pentiums of up to 133 MHz speed only, while others will go to 200 MHz. Obviously, the second one will give you more room to upgrade if you are starting with a P133.