If you ever want to listen to music from a favorite movie, you may want to listen to the soundtrack. That is because the soundtrack is the music sung and used correctly for that movie. If you watch the movie, you will hear part or most of the song at some point during the movie. Cast recordings are similar to soundtracks, and they are precisely what the words state.
They are the recordings made from the cast of a film or play. They are usually recorded straight from the performance and not recorded later or before. Soundtracks contain other things besides just the songs heard in the movie. They also include remixed songs and sound effects. There is no distinct label used for a soundtrack.