Relay (input/output device)

A relay is an electronic switch that uses a small electrical current to control a larger current or voltage. It consists of an electromagnet and switching contacts. When the small current energizes the electromagnet, it pulls the contacts together, allowing a bigger current to flow through. When the current stops, the contacts open, stopping the flow. Relays are used to isolate different parts of a system, control high-power devices with low-power signals, and provide safety and automation in electronic systems. They allow circuits to be controlled remotely or automatically without direct human interaction.