What is the meaning of Soundtrack?

A narrow strip running down a movie film that carries the recorded sound in synchronization with the pictures.

The sound (especially the music) component of a movie, video game, etc.

A recording of such music for sale.

A background sound that is part of a larger event.

To provide, or to act as the sound or music component of a film.

soundtrack (narrow strip running down a movie film that carries the recorded sound in synchronization with the pictures)

soundtrack (the sound (especially the music) component of a movie)

soundtrack (recording of such music for sale)

soundtrack

Source: wiktionary.org