It's a new form for metadata, with which, DVDFab will output the file with the correct information and also output to a nfo file (Including the correct movie name, released date, description, genre, poster and background etc.), so that your media server, such as Kodi, Plex and EMBY will read the nfo file and show the correct movie/TV show information for you. Please check this page for more information.
If you don't want the file created, you can disable the .nfo file in DVDFab Common Settings > General > Meta to uncheck the option "I want to use Meta information".