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What Does Motherboard Mean?

A motherboard is a computer’s main circuit board, and it includes the following attached to a fixed planar surface:

  • Input/output ports
  • Peripheral connections
  • PCI expansion slots
  • Bus and power connectors
  • Heat sinks and mounting points for fans and major components, including the central processing unit (CPU) and optional coprocessors
  • Supporting chipset for CPU, bus and external components
  • BIOS
  • Memory sockets for RAM, ROM and cache
  • Interconnecting circuitry

Additionally, daughterboards and mezzanine cards, installed on a second level, may be plugged into the motherboard. A daughterboard may be the actual motherboard and/or card or board plugged into the motherboard.

The motherboard is also referred to as the main board (mobo), system board or planar board. Apple computers refer to the motherboard as the logic board.

Techopedia Explains Motherboard

The Advanced Technology (AT) motherboard is the most common and is based on the IBM AT motherboard – a design improved with the Advanced Technology Extended (ATX) specification.

Components such as external storage, video display, sound controllers and peripheral devices may be attached to the motherboard. However, these components are increasingly integrated into the motherboard. For example, disk controllers, graphics controllers supporting 2D/3D graphics and TV input, sound card output, fast Ethernet network controller, USB 2.0 controller (with up to 12 USB ports), an infrared data communication IrDA controller (for mobile phones and printers) and temperature, voltage, and fan-speed sensors all may be contained within the motherboard.


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Margaret Rouse
Technology Expert
Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.