Using iMovie, you can create rich, full sound tracks for your movies. You can include four types of sound in your movies, which are the following:
Native sounds When you import clips into iMovie, any sound that was part of those clips comes in, too. If your clips had sound, you've already heard it numerous times while you were assembling your movie from those clips. You can use iMovie tools to control some aspects of your movie's native sounds.
Sound Effects You can add sound effects to your movie to bring it to life. You can use iMovie's built-in sound effects, and you can import other sound effects to use.
Narration If you want to explain what is happening in a movie or add your own commentary, you can record narration ...