TV and Movie databases come in handy when you are building your own media center (OSMC or Kodi for example). These databases provide all the meta data about any show or movie you might have. So that includes poster art, show descriptions, genre information and even a star ratings.
Some Great Databases
Some of these databases have their own APIs so developers can integrate them into their Apps.
Easy to Contribute
The Movie DB has a nice clear way of showing what assets are needed for a movie or TV show. You just login to edit if you have something the database doesn’t.