A 5V Relay Module is an electronic component used in circuits to control higher voltage or current devices using a lower voltage signal. It consists of a coil (usually powered by a low voltage source) and one or more sets of contacts. These modules are used in a wide range of applications where it's necessary to control devices that operate at higher voltages or currents. This is a versatile and commonly used component in electronics projects, providing a convenient way to switch high voltage or current loads using low voltage control signals. 5V Relay Module comes with different contact ratings, which determine the maximum voltage and current they can switch.