Normally open (N.O.) – without activating the switch, the contact is open.

Normally closed (N.C.) – without activating the switch, the contact is closed.

Single pole single throw (SPST)/Form A – activating the switch opens or closes the connection of one circuit.

Single pole double throw (SPDT)/Form C – activating the switch opens or closes the connection of one circuit to one of two.

Double pole single throw (DPST)/Form AA – activating the switch opens or closes the connection of two circuits.

Double pole double throw (DPDT)/Form CC – activating the switch opens or closes two circuits.

Momentary – the switch is closed or open only when the switch is activated.

Latched or maintained – the switch remains closed or open until the switch is activated again.

Feedback – the switch indicates that it has been activated; for example,
visual (light), audio (click).

Rating – the maximum voltage and/or current that the switch can handle without damage.