A relay module that has four 5V relays with the associated switching, as well as isolating components, is known as a 5V 4-channel relay module. This relay module will make interfacing easy with a sensor or microcontroller. This relay module is a convenient board used mainly for controlling high voltage, high current loads like electrical motors, lamps, AC loads & solenoid valves. This module is mainly designed for interfacing with microcontrollers like PIC, Arduino, etc.