This tutorial guides you through the use of Libraries and Events within iMovie. You'll see different examples of how to create multiple libraries and move your video footage to external hard drives if you run out of space and a basic understanding of how the file structure works using Apple iMovie.
Video files take up a lot of space and can cause you to run out of room on your Mac, so by creating and organizing your iMovie Libraries, you can copy to an external hard drive to free up space. But most importantly, you know where your files actually live!