Cables and Connectors

When it comes to technology, there are different ways to establish physical connection with different devices. This article discusses the types of cables and connectors that are commonly used.


In information science, connectors, normally called input-output connectors (or I/O for short), are interfaces for linking devices by using cables. They generally have a male end with pins protruding from it. This male plug connector is meant to be inserted into a female part (a female plug connector, also called a socket), that includes holes for accommodating the pins. However, there are hermaphroditic plugs which can act as either male or female plugs, and can be inserted into either one.

Pin Layout

The pins and holes in connectors are usually linked to the electric wires that form the cable. The pin layout describes which pins couple with which wires.

Each numbered pin generally corresponds to a wire within the cable, but sometimes one of the pins is left unused. Additionally, in some cases, two pins may be linked to one another - this is called a bridge.

Input and Output Connectors

The computer's motherboard has a certain number of input/output connectors located on the rear panel. Connectors on the rear panel

Most motherboards have the following connectors:

  • Serial port: it uses a DB9 connector, for connecting older devices.
  • Parallel port: it uses a DB25 connector, mainly for connecting old printers;
  • USB ports : 1.1, low-speed, or 2.0, high-speed, for connecting more recent peripherals.
  • RJ45 connector: called the LAN port or Ethernet port, it is used for connecting the computer to a network. It interfaces with a network card built into the motherboard;
  • VGA connector: called SUB-D15, it is used for hooking up a monitor. This connector interfaces with the built-in graphics card.
  • Jacks: (Line-In, Line-Out, and microphone), for connecting speakers or a hi-fi sound system, as well as a microphone. This connector interfaces with the built-in sound card.

Photo: Unsplash

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