title: request.headers vs. request.environ
body: <p>I'm working with Bottle.py and Python and I'm a little confused as to the difference between the <code>request.headers</code> VS <code>request.environ</code> variables.  I'm using sessions and my session data appears in the <code>request.environ</code> variables when I enumerate the data, which leads me to the conclusion that some of this data isn't public. </p>
  
  <p>How do I know which variables are public and which aren't?  What's the difference between these two variables?</p>