In its broadest sense, a soundtrack comprises everything you hear in a movie, like the sound effects, dialogues, music etc.

The soundtrack of a film is created as part of its post-production process. At first, the dialogues, sound effects, and music are developed as separate tracks like the dialogue track, sound effects track and music track. They are then mixed together to make a "composite track", which is what we hear in films. Hence it's importance. In fact, the relation between films and music is such that a film remains incomplete without the other.

Soundtracks, as we know, help to build the tone and mood of a film. At times when they are too good, the track remains as important as the film.

One of the most quoted examples in this context is the soundtrack of the classic film "Titanic". The song "My Heart Will Go On" sung by Celine Dion successfully enhanced the story of the ill-fated lovers, and gave a perfect aura to the film. Even today, not many of us can think of the film without the song lingering in our minds.