Momentary Push Button Switch

How the momentary push button switch work?
Assumptions a Push Button Switch electrical circuit is "Push to make" Normally Open - NO, no matter is SPST or SPDT contact circuit are common type switch, a Momentary Push Button Switch the circuit is open (off) when the button isn't pressed and it closes (on) when pressed or holding it down. As soon as you release the button, it automatically back to original position (free position), and the electrical circuit returns to default state.