Question: What is SOAP?

Answer: SOAP is an XML-based protocol for exchanging information between computers. Although SOAP can be used in a variety of messaging systems and can be delivered via a variety of transport protocols, the main focus of SOAP is Remote Procedure Calls (RPC) transported via HTTP. Like XML-RPC, SOAP is platform independent, and therefore enables diverse applications to communicate with one another.

To get a quick sense of SOAP, here is a sample SOAP request to a weather service (with the HTTP Headers omitted):

<?xml version='1.0' encoding='UTF-8'?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://www.w3.org/2001/09/soap-envelope" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<SOAP-ENV:Body>
<ns1:getWeather xmlns:ns1="urn:examples:weatherservice" SOAP-ENV:encodingStyle=" http://www.w3.org/2001/09/soap-encoding>
<zipcode xsi:type="xsd:string">10016</zipcode>
</ns1:getWeather>
</SOAP-ENV:Body>
</SOAP-ENV:Envelope>