title: PHP Login, Store Session Variables
body: <p>Yo. I'm trying to make a simple login system in PHP and my problem is this: I don't really understand sessions.</p>
  
  <p>Now, when I log a user in, I run session_register("user"); but I don't really understand what I'm up to. Does that session variable contain any identifiable information, so that I for example can get it out via $_SESSION["user"] or will I have to store the username in a separate variable? Thanks.</p>