Strictly speaking, SOAP and REST aren’t directly comparable: REST is an architectural style, and SOAP is a specific protocol defined by a standard.. SOAP specifies exactly how to encode an HTTP header and an XML file so that a program in one computer can call a program in another computer and pass along information. After SOAP was first introduced, it became the underlying layer of a more complex set of web services , based on Web Services Description Language (WSDL), XML schema and Universal Description Discovery and Integration (UDDI).
PostProcess(xml, envelopeKey) – a method that receives the the assembled request XML plus envelope key, and returns a processed string of XML. SOAP web services, such as JAX-WS, are useful for asynchronous processing and invocation. XML Information Set was chosen as the standard message format because of its widespread use by major corporations and open source development efforts.
The Web Services Description Language ( WSDL ) describes a common set of rules to define the messages, bindings, operations and location of the service. On the server side you will notice that the SOAP package relies on some XML Parser to parse the SOAP messages.
Since Web protocols like HTTP are installed and running on all operating systems, SOAP allows clients to invoke web services and receive responses independent of language and platforms. It processes the SOAP header blocks targeted at it and acts to forward a SOAP message towards an ultimate SOAP receiver.
Both SOAP web services and RESTful web services have proven their ability to meet the demands of the largest enterprise organizations in the world, while at the same time being able to service the smallest internet of things devices or embedded applications in production.