This is a list of grading systems by countries.

A B movie is a low-budget commercial motion picture that is not an arthouse film. In its original usage, during the Golden Age of Hollywood, the term more precisely identified a film intended for distribution as the less-publicized, bottom half of a double feature. Although the U.S. production of movies intended as second features largely ceased by the end of the 1950s, the term B movie continued to be used in the broader sense it maintains today. In its post–Golden Age usage, there is ambiguity on both sides of the definition: on the one hand, the primary interest of many inexpensive exploitation films is prurient; on the other, many B movies display a high degree of craft and aesthetic ingenuity.