A relay is an electrically operated switch that allows one circuit to control another without direct connection. Essentially, it acts as an intermediary to open or close electrical contacts, making it ideal for situations where circuits need to be controlled by low-power signals. Relays have a wide range of applications, including in electrical appliances, control systems, telecommunications, and automation processes. They are pivotal in ensuring the safe and efficient operation of complex electrical circuits.

    Relays operate by using an electromagnet that, when energized, causes mechanical contacts to either open or close. This action allows the relay to control the flow of electricity through different circuits, even if the controlling circuit operates at a significantly lower voltage or current. There are various types of relays, including electromagnetic, solid-state, and reed relays, each serving different functions depending on the application.