Noir is a detective film genre that originated in the 1940s. It is characterized by its dark, brooding atmosphere and morally ambiguous characters. NOIR films often feature crime, violence, and moral ambiguity, and often have a pessimistic outlook. NOIR films typically feature a protagonist who is a hard-boiled detective, and often feature a femme fatale. NOIR films are often set in urban environments, and often feature themes of corruption, betrayal, and revenge.