difference between SOAP and WSDL

Question

i was going through web service concept.In general the internet is working based on HTTP as application protocol and TCP as transport protocol.Then where does SOAP fit here. web service is an inter operable mechanism done by using XML format. If WSDL describes webservice data in terms of XML do we need an XML based SOAP protocol. What we can do is just send the WSDL languauge(i guess it is created by visual studio based on our web service) over HTTP, can some body brief about this.

one more question Restful service doesnot contain WSDL??

Answer 1

That's a lot of question to ask.

Web services (and partially WebAPIs) use XML for the transport language of data. That transport language has a defined interface that is shown by the WSDL (which is also XML). WSDL does not describe the web service in terms of XML, but rather it describes the web service using XML as a language.

SOAP (which is also an XML based transport language) is another wrapper around the web service's data (which is in XML). W3C calls it a messaging framework for web services. They a very thorough primer on their web site, pretty pictures and all!

RESTful services usually do not contain WSDL because they are not technically a web service. WSDL stands for Web Service Definition Language . You can however, have RSDL which is the RESTful equivalent of WSDL.

While RESTful services and web services can do the same things, they are not implemented using the same methodology.

Web services are all XML based transports. RESTful services are mostly JSON with some XML scattered among them.