A relay is an electrically operated switch that allows a low-power electrical signal to control a higher-power circuit. It typically consists of an electromagnet, a set of contacts, and an armature. When an electric current flows through the coil, the magnetic field generated attracts the armature, causing the contacts to either open or close, depending on the relay type. This action allows the relay to control the flow of current in another circuit.

    Relays come in different forms, each suited to specific applications. The most common relay types include electromechanical relays (EMR), solid-state relays (SSR), and hybrid relays. Electromechanical relays are known for their physical contacts and mechanical movement, while solid-state relays use semiconductors for switching, offering faster response times and greater durability.