Film noir is a cinematic term used primarily to describe stylish Hollywood crime dramas, particularly those that emphasize cynical attitudes and sexual motivations. Hollywood‘s classic film noir period is generally regarded as extending from the early 1940s to the late 1950s. Film noir of this era is associated with a low-key black-and-white visual style that has roots in German Expressionist cinematography.
The above description was sourced from ikipedia,