Tail lights are vehicle-mounted illumination devices positioned at the rear, signaling braking and turning intentions to following drivers. Assemblies incorporate incandescent, halogen, or LED light sources for both stopping and tail lamp functions, often combined with directional indicators. Modern designs utilize polycarbonate lenses for impact resistance and sealed housings to prevent moisture ingress. Wiring harnesses connect to the vehicle’s electrical system, regulated by dedicated circuits and relays. Some assemblies integrate rear fog lamps or backup lights for enhanced visibility.