Functionally, a PURL is a URL. However, instead of pointing directly
to the location of an Internet resource, a PURL points to an
intermediate resolution service.  The resolution service associates
the PURL with the actual URL and returns that URL to the client, which
can then complete the transaction in the normal fashion.  In Web
parlance, this is a standard HTTP "redirect."
<!--
<pre>
     _______         PURL       ---------- 
    |        |  ------------&gt;&gt; |          |
    |        |                 |   PURL   |
    |   C    |       URL       |  SERVER  |
    |   L    |  &lt;&lt;------------ |          |
    |   I    |                  ----------   
    |   E    |       URL        ----------              
    |   N    |  ------------&gt;&gt; |          |                                 
    |   T    |                 | RESOURCE | 
    |        |    Resource     |  SERVER  |     
    |        | &lt;&lt;------------  |          | 
     --------                   ----------      
</pre>
-->
<p>
More information about PURLs is available in the <a
href="http://purl.oclc.org/OCLC/PURL/FAQ"> PURL FAQ</a>.