title: Why facebook login doesn't ask me for my email and password
body: <p>I simply walked through <a href="https://developers.facebook.com/docs/tutorials/ios-sdk-tutorial/authenticate/" rel="nofollow">this</a> and <a href="https://developers.facebook.com/docs/tutorials/ios-sdk-tutorial/personalize/" rel="nofollow">this</a> official facebook tutorial</p>
  
  <p>My email and password are important to be really authenticated, right ?, so why facebook SDK doesn't ask for for them. When i click on login button, it's directly get me logged in and display my name and porfile picture.</p>
  
  <p>I am asking such question because i will integrate the facebook SDK in my application to allow user to log in with Facebook, so i need to understand why the authentification process isn't the standard one which is used on the real Facebook Website? Thanx.</p>