A space station was an artificial structure in space, often built to support life. Space stations could serve many purposes, including research, defense and starship maintenance. Depending on their purpose, they may be referred to with another term, such as a Spacelab or outpost. Space stations could be in orbit of a planet, or be completely free floating in space.
Space stations were used by the Federation, the Cardassians and other races. They could be used as outposts often located in 'frontier' areas or along interstellar borders, research stations specialized in scientific research, shipyards specialized in the construction of starships, or as an orbital component of a Starbase such as a spacedock.
Stations that were positioned on the edge of the Federation border (like Deep Space K-7) or, in the case of Deep Space 9, in neutral territory close to the Federation border, were labeled as Deep Space stations.