Film Format refers to the various dimensions of film used to take photographs. The characteristic that film format primarily describes is the size of the film and the type of camera that uses the given film. Film format can be either standard size (35 mm), medium format (between 35 mm and 4″ x 5″) or large format (4″ x 5″ or larger).
Expert photographers tend to use medium format film due to the fact that it provides a higher resolution (and, therefore, greater detail) in the resulting printed photo. Similarly, medium format film allows a photographer to manipulate the final print’s size, making it either bigger or smaller without affecting the quality or making it grainier.

While the large film format offers the highest resolution, it doesn’t allow for the same manipulation that the medium format does. If a photographer tries to change the print size in the large format film, the photo will suffer from graininess.
However, medium format film is not only more expensive and less available, it also requires special film developing. Generally, only professional developers or specialty photo shops will have the capability to develop medium format film. Another drawback to medium format film is the fact that it offers less shots per roll (usually only 12 to 16 exposures, versus 24 to 27 on other film formats).