How does passport control work?

When you go through passport control. How does it work? You give them yourpassport and they check its you. But like how do they KNOW its you? What if you do like that thing in 007 where they cut the picture out of the id and change it? Or do they have like a massive database of photos lol xD. But yeah like also, if you lose your passport and dont have an entry stamp, how do you get out. Noob questions but im interested.

I believe that as of 2008 or 2009 all US passports will have RFID tags embedded in them.  Personally I find it creepy, which is I why I'm happy I got mine several years ago.  I suppose when I get my new passport later one I'll just throw it in the microwave for a few seconds.