A push switch (button) is a momentary or non-latching switch which causes a temporary change in the state of an electrical circuit only while the switch is physically actuated. An automatic mechanism (i.e. a spring) returns the switch to its default position immediately afterwards, restoring the initial circuit condition.

The real use of these devices is in seeing, live, who is at your door as part of your front door security. For that you need a WiFi connection so you can be alerted on your phone then see who is at your door, live. So, yes, in most cases your wireless doorbell will need WiFi and will likely come with that onboard.