| ADO.NET Programming in Visual Basic .NET |
By Steve Holzner, Bob Howell
|Table of Contents|
XML Web Services are the latest big thing if you believe all the hype. What they are really is another way to implement remote components . In the past we had remote automation, Distributed COM, and COM+. These are proprietary Microsoft technologies. XML Web Services is a standards-based technology based on SOAP and XML. The other feature of Web Services is the discovery component, UDDI and Web Services Description Language (WSDL). UDDI is itself a Web Service that allows subscribers to search for and use other Web Services. The WSDL (pronounced wisdel) document describes the Web Service and is used by UDDI and the client application to discover what interfaces (properties and methods ) the Web Service exposes for client use. If it helps, you can think of the WSDL document as the analog of the type library in COM+ terminology. Of course, the WSDL document is itself an XML file.