What do you understand by auxiliary relay?

An auxiliary relay is an electromechanical or solid-state device used in electrical systems to control circuits and provide additional functions beyond the primary relay's capabilities. It typically serves to enhance circuit control by acting as a switch to open or close contacts based on the input from another relay or control device. Auxiliary relays are often used for signaling, protection, and automation purposes in various applications, including industrial and power systems. They help improve system reliability and efficiency by allowing for complex control logic and interlocking.