Film noir refers to classic crime dramas from the 1940s-1950s known for their dark visual style in black and white. Key characteristics include low-key lighting that casts shadows, urban settings like dark streets and alleys, and use of music to build tension during scenes of violence or murder. Film noir often relies on facial expressions to convey emotions like fear or shock without explicitly showing violent acts. Common visual elements include use of Venetian blinds to imply a sense of characters feeling trapped.