CPU

• The Central Processing Unit is the “brains” of a computer. It consists of an arithmetic logic unit, which performs mathematical operations, and a control unit, which directs the operation of the computer. The speed of the CPU, as measured in gigahertz, largely determines the overall speed of the computer.
  
  

BIOS Chip

• The Basic Input/Output System chip contains software for the motherboard. It identifies and configures hardware such as the CPU, display and hard disk, and checks that all hardware is working correctly. If the BIOS is configured incorrectly, a computer may not boot at all.
  
  

RAM

• Random Access Memory acts as a storage space for the computer's operating system processes, as well as the programs and data it is currently using. RAM consists of microchips mounted on small printed circuit boards known as memory modules, which plug directly into the motherboard.
  
  

Power Connector

• The power supply of a computer has special connectors that attach to the motherboard to provide power for the CPU, memory and other components. The standard, 24-pin ATX power connector is polarized so that it can only be plugged into the motherboard in one direction, thereby avoiding the risk of burning out the power supply or the motherboard.
  
  

Chipset

• The chipset is a system of integrated circuits built onto the motherboard which determines the type of processor, RAM and other devices that the motherboard supports. The chips in the chipset are electronic interfaces through which these devices interact.
  
  

Serial ATA Connector

• Serial Advanced Technology Attachment hard disk drives -- which have data transfer speeds of 3 gigabits per second and storage capacities of 1 terabyte or more -- have become the norm for personal computers, so almost all motherboards have one or more compact SATA data connectors. SATA drives are faster than Integrated Drive Electronics drives and have smaller, thinner cables, which improves airflow inside a computer.
  
  

Battery

• The motherboard battery -- typically a lithium-ion battery -- supplies the motherboard with the small amount of power it needs to maintain essential settings, such as the date and time, when the main power is turned off. Removing the battery resets the BIOS settings.
  
  

Floppy Drive Connector

• The advent of CD, DVD and Blu-ray has lead to the phasing-out of floppy disk controllers, but some motherboards still have one. Floppy disk drives connect to the motherboard with a flat, gray ribbon cable, similar to that used for IDE hard disk drives.
  
  

USB Ports

• Most modern computers have Universal Serial Bus ports on the rear of the motherboard. Manufacturers also often include one or more USB headers, so that you can connect extra USB ports if necessary. The USB 3.0 standard is backwardly compatible with the previous version, USB 2.0.
  
  

PCI Express Slots

• Peripheral Component Interconnect Express slots are the most common connections for graphics cards. PCI Express 16x slots offers a data transfer rate, or bandwidth, of 250 megabytes per second, 500 megabytes per second or 1 gigabyte per second, depending on the exact version.