Web services hold the promise of revolutionizing the way that organizations of all kinds share data. They provide a standard, universal means of data exchange that is well within the grasp of the average programmer. And beyond that, they are remarkably easy to get started with.
For those who are new to the subject, web services are modular applications that can be described, published, located, and invoked over standard Internet protocols using standardized XML messaging. Applications use the XML-based SOAP for the exchange of information in a loosely coupled , distributed environment. Applications posted to the Web are described with the Web Services Description Language (WSDL) and registered with a private or public service registry using the UDDI standard, such as http://uddi.microsoft.com or http://uddi.ibm.com .
This chapter shows you how to deal with a number of common web service scenarios and overcome some of the typical problems you might encounter. Detailed coverage of web services would require an entire book. For a tutorial on web services, we recommend Programming .NET Web Services , by Alex Ferrara and Matthew MacDonald (O'Reilly).