A single-pole single-throw (SPST) switch is an electrical switch that controls the flow of electricity to a single circuit. It has two terminals, and when the switch is turned on, the circuit is completed and electricity can flow. When the switch is turned off, the circuit is broken and electricity cannot flow.
Single-pole switches are commonly used to control lighting, but they can also be used to control other electrical devices, such as fans or pumps. They are relatively easy to install, and they are available in a variety of styles to match any dcor.