Film noir refers to stylish crime dramas produced in Hollywood from the 1940s to 1950s. These films are characterized by gloomy lighting, shadowy urban settings, and morally ambiguous protagonists. A defining element is the femme fatale - a mysterious and deceptive woman who often leads the protagonist into danger through her beauty and manipulation. Film noir was influenced by German Expressionism and adapted from American literary works, featuring themes of paranoia, guilt, and moral corruption. Famous noir directors included Orson Welles, John Huston, Billy Wilder, and Fritz Lang.