what is the difference between digital and not digital film?

Regular movies (also known as analog movies) are on film stock. They go through a film projector to show them.

A digital movie is actually a bunch of 1s and 0s, digital information, which gets sent on a disk or through a connection to a machine which stores them as computer data. This machine is attached to a projector, which converts the data into a picture and sound. There is no film involved.

Most movies are shot on digital cameras and are later put onto film. Yes, there are still some films that use film as the primary medium of recording, but there are fewer of them all the time; film is expensive, and they shoot a lot of film to make a movie. Digital cameras are less expensive to use, although they may cost a bit to buy. However, some people prefer the look of film, especially for certain types of movies.

IMAX/3D cinemas tend to keep their films digital because it is cheaper and it will last longer. Every time a film goes through the projector it has a huge risk or scratching and getting damaged. Whereas digital films will not have this problem.

Digital film uses pixels, the quality is only as good as long as there are a lot of pixels. A lot of studios are using it now because digital film is a lot easier to edit and to distribute. Though digital projectors themselves are very expensive.

Non-digital film is usually on 35mm film. 35mm film is very slowly falling out of use because you need to make thousands of copies of a film to distribute it to all theaters nationwide. It's much more time consuming and expensive than digital.

IMAX and IMAX3D are almost always converted into digital because with digital you can improve the definition (with an expensive enough projector). IMAX is a 10x larger screen than a screen that would have 35mm film, and the detail is exactly the same. If you tried to make a 35mm film larger you would have a loss of quality. So in theory the detail is 10x better, assuming of course you want to watch it on such a large screen. On a smaller screen there wouldn't be a significant difference.

well the question is simple

Digital means its not on film

non digital would be on film

because digital is how most theatres work these days

why bother with rolls of film when they can probably all be on a computer (look in a projection room)