Motherboard

A motherboard is the main circuit board in a PC. All the components in a PC are either located directly on the motherboard or connected to it so they can communicate with the CPU and with each other. Common items located on the motherboard include PCI/PCI Express slots, AGP slot, CPU socket, chipset, RAM slots, hard drive connectors, CMOS battery, mouse/keyboard ports, parallel port, USB ports and power supply connection.

Motherboard Form Factors

A PC will use one of these form factors which relates to the size and configuration of the motherboard, case and power supply. ATX is the most common form factor used for PCs.

ATX
ATX is the default form factor for current computer systems. ATX motherboards are similar in size to Baby AT motherboards, but the position of the CPU and expansion slots were changed to offer more room for expansion cards. ATX was created in 1995 by Intel.
(Balanced Technology Extended) BTX
Form factor that was supposed to replace ATX in 2005, but has yet to be embraced by users. BTX motherboard layouts are designed for more efficient cooling.
Mini-ATX
Small ATX motherboard that can be used with standard ATX cases and power supplies.
AT (Full AT)
AT was released by IBM in 1984. It was the first widely used form factor.
Baby AT
Smaller version of the AT form factor that was the industry standard from 1993 to 1997.
MicroATX
ATX based motherboard used in small form-factor systems.
FlexATX
Version of the ATX form factor that gives more flexibility in the size and shape of cases and motherboards.
LPX
Form factor that was popular in the 90's. There were no official LPX specifications.
Mini LPX
microBTX/picoBTX
NLX
Mini-ITX
PC/XT
WTX (Workstation Technlogy Extended)

Chipset

The chipset is a group of chips located on the motherboard that work together to control the data being sent and received by the CPU. The CPU requires the help of the chipset to do its processing tasks. On Intel based systems, the chipset is known as the northbridge and southbridge.