title: What is the difference between session_unset() and session_destroy() in PHP?
body: <p>From the <a href="http://php.net" rel="noreferrer">php.net</a> documentation:</p>
  
  <blockquote>
    <p><strong><a href="http://php.net/manual/en/function.session-destroy.php" rel="noreferrer">session_destroy</a></strong> — Destroys all data registered to a session</p>
    
    <p><strong><a href="http://php.net/manual/en/function.session-unset.php" rel="noreferrer">session_unset</a></strong> — Free all session variables</p>
  </blockquote>
  
  <p>My three part question is:</p>
  
  <p>The two functions seem very similar.<br>
  What is really the difference between the two?</p>
  
  <p>Both seem to delete all variables registered to a session. Does any of them actually destroy the session itself? If not, how do you accomplish this (destroy the session itself).</p>
  
  <p>Is it correct that neither of the two functions deletes the session cookie at the client?</p>