DARK TECHNO

Dark techno is typically used to describe a techno song that has an overall dark vibe (sort of heavy and serious). It could be because of the bass and the synths. The rhythm of the song can be fast as well as slow and is generally hypnotic.
The definition of dark techno changes a lot, since the genre can be interpreted differently. So generally a techno song that sounds darker than usual can be described as a dark techno song.