Hazard lights are warning lights on a vehicle that indicate a potential hazard or emergency situation. They are activated by pressing a button, usually marked with a triangle symbol, and cause all turn signal lights to flash simultaneously. This alerts other drivers that the vehicle is stationary or moving slowly due to an issue. When activated, hazard lights are commonly used during breakdowns, accidents, or when a driver needs to stop unexpectedly. They help improve safety by making the vehicle more visible to others on the road, reducing the risk of further accidents.