Similar to the album, a single can mean many things. Typically, however, a single is a very short CD-based recording, usually 2 to 3 songs in length. These are most often used in the Japanese music industry to promote new artists, but many other countries utilize them as well, only less overtly. A single typically consists of the title track, or A-side, and another track, playing a sort of filler role, or B-side. There may also be one more song, typically a remix of the A-side or a live version of an earlier song.