A music synchronization license, or "sync" for short, is a music license granted by the holder of the copyright of a particular composition, allowing the licensee to synchronize ("sync") music with some kind of visual media output (film, television shows, advertisements, video games, accompanying website music, movie trailers, etc.
A sync license allows for the coordination of music with visual elements (movies, TV shows, commercials, etc.), enabling the use of copyrighted compositions in various forms of multimedia content.