Simple Object Access Protocol (SOAP)
is just a messaging protocol useful with WSDL.
A SOAP message is divided into a messaging header and a message body.
SOAP facilitates the actual sending of the input and output messages of WSDL:
  <soap:Body>
   <m:GetStockPrice xmlns:m="http://www.example.org/stock">
    <m:StockName>IBM</m:StockName>
   </m:GetStockPrice>
  </soap:Body>

SOAP performs several useful technical functions in sending such messages and can run on top of other protocols such as HTTP and SMTP.
Just because a CIT service uses SOAP does not mean it is a web service.
In fact, focusing on this low-level commonly-used transport mechanism causes industry to lose sight of the potential of web services.



©2012 Charles Petrie - permission to reproduce widely with attribution.