A dock connector is a connector used to attach a mobile electronic device simultaneously to multiple external resources. The dock connector will typically carry a variety of signals and power, through a single connector, to simplify the process of docking the mobile device. 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.

The dock connector was originally associated with laptops, but other mobile devices use the concept.

Laptops

Docking connectors for laptop computers are usually embedded into a mechanical device that supports and aligns the laptop and sports various single function ports and a power source that are aggregated into the docking connector. Early docking connectors would carry keyboard, serial, parallel, and video ports from the laptop and supply power to it. Often these ports were available on the laptop itself, giving rise to the term "port replicator" for simpler docks. More complicated docks are usually termed docking stations, but both will have some sort of docking connector. As laptop interfaces evolved, so did the functions carried by the dock connector. The keyboard and serial ports changed to PS/2 connector for the keyboard and mouse. Now, USB is almost universal and DVI is common. eSATA and FireWire ports are also carried through the docking connector.
[edit]Mobile devices

Many mobile devices feature a dock connector. The simplest form of the dock connector today takes the form of a simple cable with the dock connector on one end and a USB connector on the other. This cable only has the USB signals in the dock connector, but is sufficient to synchronize and charge the devices. At the other end of the spectrum, dock connectors are used to completely merge devices into a variety of accessories, both mechanically and electrically.
Because of the popularity of mobile devices, many third parties have used dock connector interfaces for accessories. This includes many variations of external speakers, including stereo systems and clock radios. Automotive accessories for the mobile devices are numerous and include charging cradles, FM transmitters for playing audio through the car's speakers and a full GPS receiver. There are also original and aftermarket cables with dock connectors for direct integration with the car's audio system and controls.