What is the use of SOAP (Simple Object Access Protocol) in .Net Web Services?
The Simple Object Access Protocol (SOAP) is a platform-independent protocol that uses XML to make remote procedure calls.
Each request and response is packaged in a SOAP message containing the information that a Web service requires to process the message.
SOAP supports an extensive set of types like the primitive types, DataSet, DateTime, XmlNode and others. SOAP can also transmit arrays of these types and objects of user-defined types.
When a program invokes a Web method, the request and all relevant information are packaged in a SOAP message and sent to the server on which the Web service resides.
A Web service receives a SOAP message and parses its contents (contained in a SOAP envelope) to determine the method that the client wishes to execute and the method's arguments.
After a Web service parses a SOAP message, the proper method is called and the response is sent back to the client in another SOAP message. The client parses the response to retrieve the result.