Docking ports (also called "docking collars") are areas of a ship or station's hull that allow for the embarking/disembarking of personnel, typically to other ships or stations. These ports typically have tunnel extensions that can reach out for attachment. They are also strengthened to take the stresses inevitably created by joining the ship to another fixture. Most vessels have more than one docking port, each with their own Airlock. Starfleet ships have ports that can be easily modified to work on many different kinds of ships and stations.
See also Exterior Connect Hardpoints