DWTrue, your post deserves a new thread... but I will try to answer.
RealTracks + RealDrums are a library of performances in audio format, recorded by many talented musicians mainly with real acoustic / electric instruments in many different genres. They are specially constructed to follow notation / chord instructions in BIAB and related PGmusic programs.

Styles are combination of RealTracks and RealDrums (and MIDI+Loops) that sound good together. Style include mixer settings + inserted FX and a basic chord progression demo. Styles are a good starting point or just examples how certain RealTracks can sound in a song.

You can totally create your own styles from RealTracks by choosing up to 24(!) Real tracks that can play simultaneously and writing your own progressions.