A movie genre where war is either the major action of the film or the essential background for the film's action. Though largely focused on combat or preparation for fighting, the genre also embraces other war-related subjects: prisoners of war, resistance fighters in occupied countries, spy activities during wartime. War can also serve as a context for highly dramatic situations though the characters may not be directly involved in the fighting.
Although war is as old as mankind, the term war film is usually restricted to movies dealing with modern warfare and situations closely allied to war or armed forces. The movies dealing with more distant historical periods are better be described as historical films.