A relay module is an electronic device that utilizes an electromechanical relay to control high-voltage and high-current loads using low-voltage signals. The relay module circuit consists of an electromechanical relay, control logic, and supporting components integrated onto a PCB. It provides electrical isolation between the control circuit and the high-power circuit it controls. A 5V relay module operates with a 5-volt control signal, commonly obtained from microcontrollers or other low-voltage sources. These modules are popular due to their compatibility with widely available 5V systems and their ease of use. They find applications in home automation, industrial automation, automotive electronics, and various other projects where reliable switching of high-power loads is required.