1. It is in some form minimalist, whether in composition or in sequencing.
2. It is created for the sole purpose of making people dance.
3. It is constructed in a manner to allow DJs to quickly and expertly mix and layer 2 or more of these compositions simultaneously.
Due to it's building-block nature, true techno is closer to hip-hop than many of the genres (such as trance and breakbeat) which it is erroneously associated with.
Gangsta: Uhh...this is Techno right?
Me: No, it's Trance you dumbfuck!
Gangsta: Whateva...shit sounds all the same to me.
(please note i am not comparing classical music to techno just illustrating a point that both forms of music are created offline and rely on repeating structures that are created by thinking and editing rather than physically playing the music)