A toggle switch works by using a lever to open or close an electrical circuit. Toggle switches are available in two types: maintained contact and momentary contact. Maintained switches stay in the position in which they are switched to, and a momentary switch does not.
Switches are designed in various types and configurations, and common types include rotary, push button, toggle, proximity, reed, momentary, pressure, rocker, magnetic, key lock, dip and thumb wheel, according to Directron.com
They can be classified by several things, such as number of poles, number of closed positions, type of contact, number of breaks, method of insulation, method of operation, speed of operation, enclosure type, protection provided to circuits and type of service.
Electrical circuits have two modes, open or "on" and closed or "off." The pole of the switch closes or opens the electrical connection and is electrically insulated from all other contact parts. Switches can be found in on-off or on-off-on configurations. A toggle switch can work in different ways depending on how many poles and switching positions are available. There are several configurations for the pole and throw toggle switches. These types are single pole single throw or SPST, single pole double throw or SPDT, double pole single throw or DPST, and also normally open and normally closed.