A dock connector may be embedded in a mechanical fixture used to support or align the mobile device or may be at the end of a cable.
Docking connectors carried interfaces such as keyboard, serial, parallel, and video ports from the laptop and supply power to it.
Automotive accessories for mobile devices include charging cradles, FM transmitters for playing audio through the car's speakers, and GPS receivers.
There are dock connector cables that offer additional capabilities such as direct integration with the car's audio system and controls.
Originally, the Apple dock connector carried USB, FireWire, some controls and line-level audio outputs.
[2][6] However, Apple does continue to sell and produce a 30-pin-to-USB cable, [7] as well as a 30-pin VGA adapter compatible with the iPhone 4, 4S, 4th generation iPod Touch, and the first three iPads.