Relays are electrically operated switches that allow a low-power signal to control a high-power circuit. A relay consists of a coil, contacts, and an armature. When an electrical current flows through the coil, it generates a magnetic field that moves the armature, which in turn opens or closes the contacts, controlling the larger current in the system. The purpose of relay functions is to control or protect electrical circuits by acting as an intermediary, ensuring that the flow of electricity is regulated based on certain conditions.

    Relay functions are classified into different categories based on their intended purpose, such as protection, control, and signaling. In most applications, relays are used to protect sensitive equipment from overloads, short circuits, or other anomalies, as well as to enable automated operations in systems that require switching between multiple circuits or settings.