title: What is the meaning of ? (question mark) in a URL string?
body: <p>What is the difference between using</p>
  <pre><code>href=&quot;../usermanagement/search_user.jsp?&quot;
  </code></pre>
  <p>and</p>
  <pre><code>href=&quot;../usermanagement/search_user.jsp?pagename=navigation&quot;
  </code></pre>
  <p>in file <code>navigation.jsp</code>?</p>