The term soundtrack now most commonly refers to the music used in a movie (or television show), and/or to an album sold containing that music. Sometimes, the music has been recorded just for the film or album (e.g. Saturday Night Fever). Often, but not always, and depending on the type of movie, the soundtrack album will contain portions of the score, music composed for dramatic effect as the movie's plot occurs.
By convention, a soundtrack record can contain all kinds of music including music "inspired by" but not actually appearing in the movie; the score contains only music by the original film's composer(s). Many Christian artists have appeared on soundtrack albums of both Christian and mainstream movies and television shows.