A relay is an electrical device that acts as a switch, allowing a low-power signal to control a higher-power circuit. It consists of an electromagnet that, when energized, creates a magnetic field. This field pulls a lever that opens or closes the circuit, enabling or disabling the flow of electricity. Relays are commonly used in various applications, such as in automobiles to control lights or in home appliances to manage power. In addition to their use in electronics, relays can also be found in telecommunications and industrial automation. They help improve safety and efficiency by isolating different parts of a system. For example, a relay can protect sensitive components from high voltages, ensuring they operate safely and effectively.