The name techno is a name given to describe a very broad genre of music and stands for "electronic dance music". Categories included in the genre include trance, electronika, gabber, breakbeat, house, and trip-hop. This music can be anything from dance music to just ambience music which is not meant to be danced to. The music can have words, but often times does not. However, there is one constant in the music: it is always mixed by a DJ. The music is almost always created with a computer, or synthesizer, with remixes of songs also made popular; it is not uncommon to find two or more songs re-mixed together to create a new unique song.
Techno music can be traced back as far as the 1970's to George Clinton, the 1980's to groups such as African Bambatta, and to the 1990's, where DJs such as Paul Van Dyk, Tiesto, Alice Deejay, and groups like ATC, Scooter, and Daft Punk (who's song Around the World can be heard right now), helped turn the genre into what it is today.
As a genre, trance is said to have begun as an off-shoot of techno in German clubs during the early 1990s. The name derived in 1991 from a project of Dag Lerner (DJ Dag) and Rolf Ellmer (Jam El Mar) called Dance2Trance. Their song "We Came In Peace" also set the original definition of trance music, a drawn out and monotonous pattern with a short but repeating voicesample. The sound was meant to work hypnotic to the listeners. Arguably a fusion of techno and house, early trance shared much with techno in terms of the tempo and rythmic structures but also added more melodic overtones which were appropriated from the style of house popular in Europe's club scene at that time. (Interestingly enough, that style of house was referred to as "club" or "Euro.") However, the melodies in trance differed from Euro/club in that although they tended to be emotional and uplifting, they did not "bounce around" in the same way that house did. This early trance tended to be characterized by the anthemic qualities described above, and typically involved a break-down portion of the song in which the beat was dropped for a few bars to focus on the melody before bringing the beat back with a renewed intensity. The sounds used in trance tended to be produced by [analog synthesizers] (or recently, digital simulations of analog synthesizers, often called [virtual analog synthesizers]), with lush "strings" providing the basis for the melodies and pads, while similar analog equipment was used to produce basic bass notes and the regimented "four-on-the-floor" drum loops. This style became instantly popular in Europe and spread very quickly. Before long, trance was spawning sub-genres such as dream trance, acid trance, hard trance, and goa. (NOTE: Goa and psy-trance are arguably older, with their characteristic sounds purportedly emerging in Israel as far back as 1991.)