12V 10A 5-Pin SPDT Sugar Cube Relay is an electromechanically operated switch. The term 12V 10A(5-Pin) SPDT means, it is a single pole double throw (SPDT) relay, having a common terminal that connects to either of two others, including two for the coil, such a relay has five terminals. With a compatible voltage of 12V, it can pass a 10A current. And for the max power rating as it is written on the product 30VDC, with 30VDC it can pass a max current of 15A.
Relays are generally used when it is necessary to control a circuit by low-power signal, or where several circuits must be controlled by one signal. It is a very must-have component for any electronic project where you need to control an AC device with a DC signal.