The terms B-side refer to the two sides of 78 and 45 rpm Phonograph Records, whether singles or extended plays (EPs). The A-side usually featured the recording that the artist, record producer, or the record company intended to receive the initial promotional effort and then receive radio airplay, hopefully, to become a "hit" record. The B-side (or "flip-side") is a secondary recording that has a history of its own. Some B-sides that were considered as strong as the A-side and became hits in their own right.