A 12V 100A relay is an electromechanical switch designed to handle large currents of up to 100 amperes while being activated by a 12-volt control signal. The "12V" refers to the voltage required to operate the relay’s coil, while the "100A" indicates the maximum current the relay can switch. This type of relay typically consists of a coil, a set of contacts, and a mechanical armature that moves when the coil is energized.

    When a small voltage (in this case, 12 volts) is applied to the relay’s coil, it generates a magnetic field that pulls or pushes the contacts together, closing or opening the circuit to allow or interrupt the flow of electricity. The 100A rating refers to the amount of current the relay can safely switch on its contacts without damage, making it suitable for high-power applications.