A feature film (or just “feature”) is a full-length film, the kind you buy a ticket for at your local theater. The term is also used to distinguish between films that are first shown theatrically versus those made for television.
A modern feature is typically between 80 and 180 minutes long, but different groups have different minimum lengths to be considered a feature. The Screen Actors Guild definition sets the minimum length at 80 minutes, while AFI and BFI’s definitions call any film longer than 40 minutes a feature. The Academy also uses the 40 minute benchmark to determine if a film is a feature or a short. The Sundance Film Festival sets the line at 50 minutes.