There are two types of VST programs: VST instruments (a.k.a. VSTi) and VST effects. VST instruments produce sounds and VST effects change sounds. A synthesizer is a common example of a VST instrument. A reverb is a common VST effect.
House music evolved from disco and, consequently, many flavors of house music do not use much distortion at all.
A common sound in trance music is a gated synth lead. Most trance musicians play a long note into a synthesizer and rapidly turn its volume up and down.