Relay Module 10A 1 Channel
A Relay is a digital switch to control much higher voltages and currents than your normal Arduino boards do. When inputs a logic voltage, the relay will switch to allow current to flow or cutoff, depending on your wiring. A Relay usually consists of a coil, 1 common terminal, 1 normally closed terminal, and one normally open terminal. When the coil is energized, the common terminal and the normally open terminal will have continuity. The terminal pitch is 5mm.
Why do we want to use a relay and do we really need to? Anytime you want to switch on/off a device that draws more current or works with a high voltage, you'll need to use a relay, such as controlling of headlights, parking lights, horns, etc. There are also the 4-Channel Relay Module and 8-Channel Relay Module for your option. Please Note that Connect the VCC to JD-VCC with the jumper when using.