title: what does UrlReferrer exactly mean?
body: <p>what does UrlReferrer(<code>Request.UrlReferrer</code> &amp; <code>Request.UrlReferrer.OriginalString</code>) exactly mean?<br>
  i wrote these codes :  </p>
  
  <pre><code>    if (Request.UrlReferrer != null)
      {
          User_Info.Add(!string.IsNullOrEmpty(Request.UrlReferrer.OriginalString) ? Request.UrlReferrer.OriginalString : string.Empty);//6:UrlReferrer
      }
      else
      {
          User_Info.Add(string.Empty);
      }
  </code></pre>
  
  <p>i just know ReturnUrl querystring when a user tries to login to admin area.<br>
  so in web.config <code>&lt;authentication mode="Forms"&gt;</code><br>
  and now we have UrlReferrer server-side code.<br>
  i want to gather some information about my users of my web site such as User-Agent , User-Browser , Session-ID , etc...<br>
  but i really do n't know what does UrlReferrer exactly do and it is always null.(i think because of wrong usage)<br>
  would you please give me a simple example for understanding.   </p>
  
  <p>thanks for attention</p>