Although the North American definition generally refers to films between 20 and 40 minutes, the definition refers to much shorter films in Europe, Latin America and Australasia. In New Zealand, for instance, the description can be used to describe any film that has a duration longer than one minute and shorter than 15 minutes. The North American definition also tends to focus much more on character whereas the European and Australasian forms tend to depend much more on visual drama and plot twists. In this way, the North American form can be understood to be a derivation of the feature film form, usually acting as a platform for aspirant Hollywood directors. Elsewhere, short films tend to work as showcases for cinematographers and commercial directors.

Early period

The term came to be applied in North America in the 1910s, when the majority of feature films began to be made in much longer-running editions. A typical film program came to be expected to include a feature preceded by one or more short subjects. Short subjects could be live action or animated. Comedy was particularly utilized, and well-known comedians such as Charlie Chaplin, Buster Keaton, Laurel and Hardy and others are known for their short films as well as their features.

Animated cartoons likewise came principally as short subjects, as did newsreels. Less frequently, short subjects might be in the form of travelogues, human interest films or concert films. The form was so popular that virtually all major film production companies had fully-staffed special units assigned to develop and produce them, and many companies, especially in the silent and very early sound era, produced short subjects exclusively (e.g. Keystone Studios, Atlas Educational Film Co., E. W. Hammons's Educational Pictures).

Rise of the double feature

The death of the two-reel short as a commercially successful product for independent studios put producers such as Mack Sennett out of business. Hal Roach moved Laurel and Hardy full-time into feature films after 1935, and halved his popular Our Gang films to one reel at the request of distributor Metro-Goldwyn-Mayer. Roach, who could no longer afford to produce shorts after 1938, sold out to MGM at that time.

After the 1930s, fewer shorts were made for theatrical release, most of which were one-reel long, like George O'Hanlon's Joe McDoakes shorts, and the animated shorts of studios like Leon Schlesinger Productions/Warner Bros. Cartoons, Walter Lantz and Fleischer/Famous Studios. These shorts and others were produced in-house by, or financed by, motion picture companies that either owned their own theater chains (for example, Loews Theatres) or forced theaters to take their shorts by selling them in the same unalterable package as their big-name features. This practice, called block booking, was declared illegal by the US Supreme Court, who also forced the theater chains to sell off their movie studios. By 1955, thanks to double features, the ban on block booking and the rise of television, the commercial live-action short was virtually dead, and the cartoon short was fading. Since the 1960s, short films have been largely reserved for independent filmmakers and special major-studio projects.