The space station in Guardians of the Galaxy is called Knowhere. It is an enormous severed Celestial head floating at the edge of space, where intergalactic travelers gather, trade, and pursue dangerous business.
In the Marvel Cinematic Universe, Knowhere initially serves as the headquarters of the Collector, Taneleer Tivan. In Guardians of the Galaxy (2014), Gamora, Peter Quill, Drax, Rocket, and Groot visit the station to sell an orb that contains the Power Stone. The location's unsettling appearance reflects its origin as the remains of a cosmic being rather than a conventional spacecraft or planet.
Knowhere is easy to confuse with Morag, the desolate planet where Peter Quill finds the orb, or Xandar, the Nova Corps' homeworld. Contraxia is another fictional world in Marvel stories, but it is not the station visited in the film.
After the events of Avengers: Infinity War, the Guardians acquire Knowhere and transform it into their base. It later becomes a community and mobile headquarters in Guardians of the Galaxy Vol. 3.