A pushbutton switch is a type of switch that opens when you take your finger off the button. When you push the button, you close the switch.

The pushbutton switch is good for doorbells. When you push the button, the doorbell rings. When you let go of the pushbutton switch, it releases by itself causing the doorbell to stop ringing.

Outside of a push button switch.	Side view of the same switch.

Push button switch - exterior	Push button switch - interior