SOAP

SOAP = RPC + XML + HTTP

The above equation summarizes what SOAP is. The acronym itself stands for "Simple Object Access Protocol".

It's purpose is to provide a platform independant way in which for objects to call methods on each other and thus access each other's functionality.

Example of SOAP data packet

POST /StockPrice HTTP/1.1
Host: www.stockpriceserver.com
Content-Type: text/xml
Content-Length: nnnn

<StockPriceServerCall>
	<GetStockPrice>
		<Symbol>MSFT</Symbol>
	</GetStockPrice>
</StockPriceServerCall>

As can be inferred from the above example, SOAP uses HTTP to transmit XML data packets that describe a method call and any parameters associated with it.

References: A