A relay assembly is a combination of a relay and other components such as wiring, connectors, and control circuits that work together to enable the controlled switching of electrical devices. The relay, the core element of the assembly, is an electromechanical switch used to control the opening or closing of a circuit. It functions by receiving a low-power input signal, which activates an electromagnetic coil inside the relay. When the coil is energized, it generates a magnetic field that moves an armature, either closing or opening the contacts, thus completing or interrupting the circuit.