In photography, film format refers to the size of the film. Some common film formats include 110, 35mm and 120.
The 110 film format is a cartridge film. The film is very small, and it's contained in a plastic cartridge that fits into specific cameras.
The 35mm format, which is the most commonly used, is the standard film size that is used in both still photography and motion pictures.
120 film, also known as medium format, is larger than 35mm film.