Patch cables act as a patch, making an electrical or optical connection between different devices.

There are many different types of patch cables, and they are usually quite short, anywhere from a few inches to several feet in length. Although they can be called patch cables, they each perform a specific function based on how they are made. A coaxial cable that connects from the wall jack to your cable television set-top box is an example of a patch cable. That cable is only useful for bridging coaxial connections (or temporarily securing the trunk of your car over your new grill.) Each type of patch cable will have its own electrical or optical properties and specifications to adhere to.

Here are some examples of patch cables:

  • The RJ-45 Ethernet cable that goes from your cable modem to your computer or network switch
  • The RJ-11 telephone cable that connects your telephone to the wall jack
  • The red and white RCA cables or optical cable that connect the audio from your DVD player to your receiver
  • The USB cable that connects your computer to your printer
  • The HDMI cable that connects your high-definition output device to your plasma display
  • The DVI cable that connects your computer to your LCD monitor

Sometimes the wiring used for the cables can be a standard gauge or other specification, but the connectors on the end, and how the connectors are wired, will end up making one cable very different from another. For example, a standard Category 5 (CAT 5) network cable can be wired in several different ways to conform to different networking standards.

A very short patch cable can also be referred to as a pigtail. If the type of connector changes between ends, the cable can also be called a dongle or adapter. One example of an adapter would be an audio cable that has RCA jacks on one end and a phono plug on the other.