At its core, a relay is an electrically operated switch. It consists of a coil of wire, an armature, a set of contacts, and a spring. When electrical current passes through the coil, it generates a magnetic field that pulls the armature, which in turn either opens or closes the contacts. This simple mechanism can control much larger electrical currents than what would be possible with a human-operated switch. Relay solutions take advantage of this feature to create highly reliable, automated systems that can respond to changes in conditions or signals without human intervention.