The S-train (, ) is an urban rail network which serves Copenhagen, Denmark, and its environs. It connects the city centre to the inner and outer boroughs and suburbs (with the exception of Amager Island). The average distance between stations is 2.0 km, shorter in the city core and inner boroughs, longer at the end of lines that serves suburbs. Of the 85 stations, 32 are located within the central ticket fare zones, 1 and 2. The S-tog is roughly analogous to S-Bahn systems in Germany, and is a separate system from the Copenhagen Metro, which operates only in the city centre.