• If a site offers a Web Service, it needs to provide some means for an external site to find out the details of the Web Service, ...
• ... i.e., what methods are provided and how they are called.
• If you go to http://www.winisp.net/cheeso/zips/ZipService.asmx?WSDL
  a WWW page describing the ZipService Web Service is produced.
• Depending on the browser you are using, you may need to click on View Page Source in order to see this text.
• The page is written using the notation of an XML language called WSDL (Web Services Description Language).
• This is a language originally developed by Ariba, IBM and Microsoft but which is now universally used. It was first released in September 2000.
• A WSDL document describes everything that is needed to contact a Web Service.
• A full description of the various parts of a WSDL document is provided by [26].
• The WSDL document at http://www.winisp.net/cheeso/zips/ZipService.asmx?WSDL
  will be needed again later ...
• ... so save the text in a file called ZipService.wsdl.