Role of DISCO - Web Services

I know every service we create (working with ASMX, .net 2.0) is attached with discovery document and I know the definition and purpose of Discovery document from numerous articles on web.

I need to know how it actually works? What do we mean when we say

It is through the discovery process that XML Web service clients learn that an XML Web service exists and where to find the XML Web service's description document.

I have never used discovery document to find or making request to the service. Or is there any ot开发者_StackOverflowher way than knowing the .asmx URL of the service to download WSDL and make a call.

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Actually, there is no purpose to it. UDDI is not actually used. It sounded like a good idea at the time, but has turned out not to be usable.

In practice, XML Web Service clients learn that an XML Web Service exists because someone tells them the URL of the WSDL file.

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Cant actually describe it better than this...

Publishing and Discovering Web Services with DISCO and UDDI