@tsarstepan,
I guess my understanding (which could be wrong) was cliques were more exclusive - in other words cliques are the "popular" kids. I know my daughters still speak of cliques differently than the do of friend groups.
I guess maybe friend groups are cliques for the "normal" kids.
Its weird - it almost like the cliques are mean to everyone that is not part of the clique and the friend groups are just mean to those within their circle when there is something a "friend" does they don't like.