Socket Guide

The following table shows pictures of PC sockets, gives their names, and their most common uses. If you have problems identifying a socket that’s not listed, please call us and we can help identify it.

If you plug a device into your PC using the incorrect socket or lead, you may end up damaging both the PC and the device!

Socket	Plug	Description
		Power Where you plug in the power; most desktop computers use the connection shown, but laptops use a wide range of different connectors and separate power supplies.
		PS/2 Normally used for mouse and keyboard – the keyboard socket & connector are often purple/mauve, and the mouse green.
		Serial or COM port Older generation machines use these instead of USB sockets.
		Parallel port Usually used to connect printers, these have been replaced in more recent machines by USB sockets, but many printers still have parallel connections. Parallel cables are limited in length to about 2 metres – anything longer and you can get signal interference causing problems printing.
		VGA Connects to a monitor. Nearly all computers will have this type of connector, although more recently some also have DVI connectors (see below)
		USB Used amongst other things for printers, scanners, digital cameras, external hard disc drives, iPods, memory keys… It comes in two flavours, USB1.x and USB2.x, the second being faster and backwards-compatible – ie you can plug a 2 device into a 1 socket and vice-versa, but the device will only work as fast as the slower component.
		Firewire Conceived for connecting digital video cameras and hard disc drives, this device runs around about the speed of USB2 or faster. The 6-pin connector is shown – there is also a smaller 4-pin version and adapters to connect the two.
		Modem/Phone Line Connects the computer to a phone line to allow dial-up access to the internet and sending and receiving of faxes. Many computers have a modem built-in, but if you have broadband, you might not need to use it – in fact, if you don’t use your modem, it’s safest to disconnect the phone to prevent phone dialler trojans.
		Ethernet Connects the computer to a local area network and/or broadband internet. Not all computers will have this type of connector, but it’s the easiest and best way to connect to the internet if you have a modem or router that supports ethernet.
		Comparison between modem and ethernet connectors These two connectors are quite similar, so this picture shows how the ethernet connector is slightly wider. In fact, the phone connector will physically fit into the ethernet socket, but you shouldn’t ever plug it in!
		DVI An update of the VGA connector for monitors and displays which use pure digital signals; some computers will have both VGA and DVI connectors; if you have the option to use DVI, it provides a better picture than VGA.