big ass: For big booty and massive buttocks lovers.
ass: Video genre that focus on the butts. It can includes anal, asslicking and rimming and even spanking, but also more generic movies that just focuses on asses, big or small.
babe: Usually softcore, this niche features girls that are considered extremely attractive. Beautiful and young female models.
teen: Sex performer that either is or appear to be nineteen or under.