A red light indicates that vehicles must come to a complete stop. It is a crucial traffic signal used to manage the flow of traffic at intersections. When the light turns red, drivers must wait until it changes to green before proceeding. This rule helps prevent accidents and ensures safety on the roads. In many places, a red light is accompanied by a stop sign or a traffic signal to reinforce the message. Pedestrians are also affected by red lights, as they should wait for the signal to change before crossing the street. Following these signals is essential for maintaining order and safety in urban areas.