title: What is the definition of an absolute URL (fully qualified?)
body: <p>There are (at least) three ways to link to a resource:</p>
  
  <ol>
  <li><code>href="foo/bar.html"</code></li>
  <li><code>href="/foo/bar.html"</code></li>
  <li><code>href="http://example.com/foo/bar.html"</code></li>
  </ol>
  
  <p>The first is a "relative url", no problem.  But I've seen (2) and (3) both referred to as an "absolute url".  Which is correctly termed an "absolute url", and what is the proper name of the other?  </p>
  
  <p>(Bonus points for references to relevant standards or other official documentation.)</p>