Simple Object Access Protocol is a standard for exchanging information over the client and server.

This is the basic structure of SOAP message exchange

<?xml version="1.0"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://www.google.com/soap-envelope" SOAP-ENV:encodingStyle="http://mydemo.com/soap-encoding">

   <SOAP-ENV:Header>
      ...
      ...
   </SOAP-ENV:Header>
   
   <SOAP-ENV:Body>
      ...
      ...
      <SOAP-ENV:Fault>
         ...
         ...
      </SOAP-ENV:Fault>
      ...
   </SOAP-ENV:Body>
   
</SOAP_ENV:Envelope>

• Envelope − It is a mandatory element which helps in defining the starting point and the ending point of the message.

• Header − Additional attributes of the message is contained in header.

• Body − The main content which have to be sent is contained inside the body.

• Fault − Fault contains information about the errors that comes while request or response

Here is an example of SOAP request

POST /Quotation HTTP/1.0
Host: www.myhost.com
Content-Type: text/xml; charset=utf-8
Content-Length: nnn

<?xml version="1.0"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://mydemo.com/soap-envelope" SOAP-ENV:encodingStyle="http://mydemo.com/2001/12/soap-encoding" >

   <SOAP-ENV:Body xmlns:m="http://www.xyz.org/quotations" >
	
      <m:GetQuotation>
         <m:QuotationsName>MiscroSoft</m:QuotationsName>
      </m:GetQuotation>
		
   </SOAP-ENV:Body>
	
</SOAP-ENV:Envelope>