Saving a muvee renders the finished output to a specified file in a format of your choice. (such as WMV, MPEG-2 or AVI etc)

Saving a muvee project preserves your work in progress as a .rvl / .mvex / .mve / .mvn file (.rvl for muvee Reveal, .mvex for muvee autoProducer 6, .mve for muvee autoProducer 5, and .mvn for muveeNow), so that you can exit from your muvee program and subsequently relaunch your project without having to start from scratch. Your media files, selected style and other settings are all preserved when you save a muvee project.