Push button

A normally open push button has separated contacts when released. Pressing it joins them; letting go lets a spring open them again. Unlike a maintained switch, it does not stay on.

This two-terminal button has no + or −. Its symbol shows the unpressed, open contacts. Keep it held if you want current to keep flowing.

At the workshop door, a visitor holds a push button to ring the bell. As soon as they let go, the bell goes quiet and Sparkie knows someone is waiting.