Favorites are a list of logical items added by user. They are links to a certain part of the 'real' video. You can select multiple favorite and play them one after another like a single file. You can also search your favorites according to descriptions. If you delete the linked video file, your favorite item will expire also. You will be prompted to delete it when trying to play an expired favorite item. To create your own favorite item, please refer to Adding Part of Video to Favorites