A traffic signal is a device used to control the flow of vehicles and pedestrians at intersections. It typically consists of three colored lights: red, yellow, and green. The red light means "stop," the green light means "go," and the yellow light warns that the signal is about to change. These signals help prevent accidents and ensure that everyone follows the rules of the road. Traffic signals are often found at busy streets and intersections, where they help manage the movement of cars, bicycles, and pedestrians. They are an essential part of urban infrastructure, working alongside road signs and crosswalks to create a safer environment for everyone.