Using an electrical or electronic component, or switches to transfer current from one route to another. In its simplest form (On -Off) to make or break a circuit. Common types of switches are: Single Pole Single Throw switches SPST, Single Pole Double Throw switches SPDT Double Pole, Single Throw switches DPST, and Double Pole Double Throw switches DPDT. SPST switches control a single wire circuit, SPDT switches control two single wire circuits, allowing only one circuit to be energized at a time.
DPST switches control two circuits simutaneously. They act as two switches actuated by a single lever. DPDT switches control four circuits, allowing only two circuits to be energized at the same time.