Relays are electrically operated switches. Wherein, single or multiple control signals operate a specific switch configuration, e.g. connect or disconnects a circuit
Relays are typically used where it is necessary to control a circuit by an independent low-power signal, or where multiple circuits need to be controlled by single signal Traditionally, relays use electro-magnets to open or close contacts (these are still wide used). Modern relays can adopt more sophisticated operating principles and configurations to achieve desired functions for specific applications. Sub-categories of relays include power relays, solid-state relays, automotive relays, etc