Genres and Topics
Movies with a non-conventional narration and/or aesthetic (normally not bound by the typical rules of the rest of cinema with regards to structure or visual syntax). These exist in complete contrast with commercial cinema which consists of movies directed to a wide audience and often deploy traditional narratives.
Topics are sub-genres and/or themes of any kind (i.e. Romantic Comedy, Buddy, World War II, Sports) that enable you to more specifically describe the plot of the movie you are looking for. Topics, however, are not keywords. If you search for a topic like "shark", for example, only movies in which sharks play a significant roll will appear, such as 'Jaws'. But not every movie that has a shark in it will be listed.