Tail lights are the red lights located at the rear of a vehicle, designed to signal the presence and actions of the vehicle to others on the road. They illuminate when the vehicle's headlights are on and become brighter when the brakes are applied, alerting drivers behind to the vehicle's movements. In addition to brake lights, tail lights often include turn signal indicators, which flash to indicate a change in direction. These lights are essential for road safety, helping to prevent accidents by making vehicles more visible, especially in low-light conditions or during adverse weather.