I'd like to turn on Google's two authentication factor on but first I'd like to understand how it works.
Specifically I'd like to use the Google app for smartphones (btw I checked the FAQ and this is not a question about smartphone but a question where smartphone are on-topic because they interface with a computer).
So I do not want to use the "receive a SMS for authentication".
My question is about the Google app: how does it work? Is everybody downloading a different app or is the app somehow "seeded" for your specific Google account?
Also what happens if you somehow lose your smartphone? How can you then re-install that Google app and how do you re-seed it (if it needs to be seeded)?
Basically I'd like to understand how Google manages to do the equivalent of a RSA device (?) using a Google app.