Motherboards

Motherboard Basics
Most computer users have probably heard the term motherboard, but if you are unfamiliar with the role of the motherboard within the overall PC architecture, or if you are not quite clear about the components that make up a motherboard, this page is a good place to start.

Definition of a motherboard
The motherboard is the primary printed circuit board in a PC. All of the basic circuitry and components required for a PC to function are either contained in or attached to the motherboard. The motherboard typically contains the system bus, processor and coprocessor sockets, memory sockets, serial and parallel ports, expansion slots, and peripheral controllers. The motherboard may be alternatively referred to as the mainboard, system board, or even maincard or mothercard, but regardless of what you call it, it is the central component that enables all of the other parts of a computer to mesh.

Components of a motherboard
The diagram below shows the component layout of a typical motherboard. Individual parts are numbered and are identified in the accompanying legend.

  1. Ports
  2. ISA Slot
  3. PCI Slots
  4. AGP Slot
  5. CPU Slot
  6. Chipset (Northbridge)
  7. Power connector
  8. Memory sockets
  9. I/O connectors
  10. Battery
  11. Chipset (Southbridge)
  12. BIOS chip

The motherboard's general size, layout, and component placement is known as the form factor. The example above is an ATX board, which is the most common form factor, but there are several other standard dimensions available.