A motherboard also known as a motherboard or motherboard is a printed circuit card that supports and connects the internal components of a computer. It also has multiple standard connectors to connect external components.


ASRock A70GXH-128M motherboard from 2012.

Evan-Amos CC BY-SA 3.0 Unported via Wikimedia Commons.

Typical elements of a PC motherboard


PS/2 connectors:

1 - Green PS/2 connector, for mouse.

2 - Purple PS/2 connector, for keyboard.

Video Connectors:

3 - VGA connector for monitor.

4 - DVI connector for monitor.

5 - HDMI connector for monitor.

Digital Audio Rear Connector:

6 - S/PDIF connector for digital audio output.

USB and Ethernet connectors:

7 - USB 2.0 type A connector.

9 - USB 3.0 type A connector.

8 - RJ-45 connector for local area Ethernet connection.

Analog Audio rear connectors:

10 - 7.1 analog audio output. Side, rear and subwoofer speakers.

11 - Analog input for microphone.

12 - Stereo analog audio output. Front speakers.

13 - Analog audio input, line level.


Expansion card connectors:

14 - PCI Express x16 connector.

15 - Battery for the CMOS memory of the motherboard.

16 and 18 - Old PCI connectors.

17 - Connector PCI Express x1.


Connectors for the box and SATA:

19 - USB connectors for the PC box.

20 - Connector for the speaker of the PC box.

21 - Connectors for the LEDs of the PC box and power button.

22 - SATA connectors for connecting hard drives, SSDs, DVDs, etc.


Other connectors:

23 - Four connectors for the memory RAM DDR4.

24 - Motherboard power connector.


Other connectors:

25 - CPU connection socket.

26 - Motherboard power connector for the CPU.