A 12V relay is an electrically operated switch that controls circuits by using a low-voltage signal to switch a higher voltage or current. The most common application of 12V relays is in automotive systems, where they are used for controlling power to components such as lights, wipers, windows, and air conditioning. These relays are essential in ensuring that the electrical systems of a vehicle operate efficiently and safely. Aside from the automotive industry, 12V relays also find use in industrial automation, home appliances, and even telecommunications, where they regulate power supply and protect sensitive electronic systems.