Better known as an optical, digital optical or fiber optic audio connection, the TOSLINK connection system (both port and cable) was originally developed by Toshiba. With TOSLINK, electrical audio signals are converted into light and transmitted through a fiber of plastic, glass or silica.

It is one of several methods for transferring digital audio signals between components in consumer audio systems.

If you look at the fiber end of a connected TOSLINK cable, you will see a red dot shining light back at you. The cable end is flat on one side and rounded on the other, so there is only one direction to plug it in.

Many wireless audio adapters, HDTVs, home theater equipment, DVD/CD players, receivers, amplifiers, stereo speakers, computer sound cards, and video game consoles feature this type of digital optical connection. Sometimes it is found in combination with video-only connection types, such as DVI or S-video.