At its core, a relay signal is a type of electrical signal used to trigger or control the operation of a circuit through a relay switch. A relay itself is an electrically operated switch that allows one circuit to control another, often with higher voltage or current. When a relay receives a signal, it activates its internal mechanism to either open or close the contacts, thereby controlling the flow of electricity in the connected circuit.

    The relay signals themselves can be digital or analog, depending on the nature of the system they are integrated into. Digital relay signals are typically used in systems requiring discrete on/off control, while analog signals are used for more complex systems that need varying levels of output or feedback.