When Does A Film Stop Being A Film?

#movies
#1
This is something that's been on my mind for a while now as I've been trying to get my first fanedit finished and up to a certain standard for the last three to four months, though I feel that my question could potentially make for an interesting discussion thread as it touches on the nature and definition of film classification.

The standard film length runtime is considered to be 1 hour and 20 minutes yet there are also TV episodes with that exact same runtime duration.

Two particular Wallace and Gromit films have the runtime of a standard  TV episode yet they are classified as films and not TV episodes, it for me at least raises the question of what truly defines a film and where the separation and categorization between Short, Episode, Short Film & Feature Film begins and ends.

Because if a media's categorization cannot be accurately defined and measured by it's runtime and if the rules set by society keep changing when a movie is considered a movie than anything that is capable of appearing on an electronic device that is capable of displaying imagery may as well all be defined under the one simple category of "Film"

What I am getting at is that based on the revolving logic of those within the film making and television industry is that a company could release a 5 second trailer for a film that is only 60 Seconds long than on the premier date show trailers that last up to an hour or more than when the actual film comes on and ends in those 60 seconds someone says.

"That was absolute cinema" simply because they were in a movie theater and payed £100 just to see a 60 second movie.

Perhaps I am making this out to be more complicated than it actually is and have already given myself the answer in my own philosophical rambling in my own oblivious poetic irony, but for those who may have found that this post caught there interest, where do you personally believe a film stops being a film?