SOAP

Simple Object Access Protocol (SOAP) is a communication protocol that defines an XML data flow between a server and a client.

Web services using the Simple Object Access Protocol (SOAP) protocol provide information about their use that developers can invoke using the Web services Descriptive Language (WSDL) to generate a WSDL document.

Each SOAP Web service must have an associated WSDL document, so that developers and applications know what to expect from the Web service, and how to invoke it.

The "StockQuote" service mentioned in the Introduction to Web services exchanges messages using the following syntax:

Response

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
   <soap:Body>
      <getQuoteResponse>
         <stockValue>999.99</stockValue>
      </getQuoteResponse>
   </soap:Body>
</soap:Envelope>

Request

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
   <soap:Body>
      <getQuote>
         <stockSymbol>MyCompany</stockSymbol>
      </getQuote>
   </soap:Body>
</soap:Envelope>

SOAP relies on a lower-level protocol for the transport layer.

Genero Web Services use SOAP over HTTP, and can also perform low-level XML and TEXT over HTTP communications on the client side. This allows communication between applications using the core Web technology, taking advantage of the large installed base of tools that can process XML delivered plainly over HTTP, as well as SOAP over HTTP.