User blog comment:DiegoAnime3000/RWBY Volume 3 Opening Scene is complete/@comment-4010415-20150612013214/@comment-4010415-20150612020046

Opening scene = The very first scene of the volume/season, the scene that the first episode starts on.

Opening sequence = The intro sequence. Y'know, where it plays basically a music video with credits on it and ends on the show's title.