Signal lights are devices used to convey information to drivers and pedestrians about traffic conditions. They typically use colors like red, yellow, and green to indicate when to stop, prepare to stop, or go. These lights are commonly found at intersections and pedestrian crossings, helping to manage the flow of traffic and enhance safety. In addition to traffic signals, signal lights can also be used in various settings, such as railroad crossings and airports. They serve a similar purpose by providing clear visual cues to ensure safe movement and prevent accidents in busy environments.