Switch type is a term used to describe the various types of switches that are available for use in electrical systems. Toggle switches, which have six letters, are mechanical switches that can be flipped back and forth to turn a circuit on or off. Onoff switches, which have five letters, are also mechanical switches that can be used to control the flow of electricity. Solenoid switches, which have eight letters, are electromechanical switches that use an electric current to activate a plunger that opens or closes a circuit.