SOAP

SOAP or Simple Object Access Protocol is an XML-based object invocation protocol that defines the use of XML and HTTP to access services, objects and servers in a platform-independent manner. SOAP was originally designed for communication of distributed applications over HTTP, and through corporate firewalls, as a framework for expressing application semantics. It did this by providing a modular packaging model and encoding mechanisms for encoding data within modules. SOAP can be applied in a variety of systems ranging from messaging systems to RPC. SOAP does not itself define any application semantics or a programming model, per se. SOAP defines protocol bindings which describe how a message can be carried in HTTP messages either with or without the HTTP Extension Framework in a distributed computing environment.
Besides the traditional request-and-response messages SOAP is capable of facilitating rich message exchange patterns and broadcasting. However, using a binary data attachment for messaging is very complex while using SOAP, and so this is generally not an option which is feasible.

• SOAP uses an Internet application layer protocol as a transport protocol usually via HTTP/HTTPS (Or SMTP). Using SOAP over HTTP/HTTPS enables easier communication behind proxies and firewalls by using other remote execution technology and other distributed protocols like GIOP/IIOP or DCOM, which in themselves become very complex because of messaging filtration by firewalls.
  
• SOAP provides communication between two operating systems by using HTTP and XML. Due to HTTP and XML being available on all major operating system platforms, this provides an immediately accessible solution to getting different operating systems to communicate. SOAP is supported in DCOM, COM, Internet Explorer and Microsoft's Java implementations.
  
• Basically, SOAP is a stateless, one-way message exchange paradigm, (although more complex interaction patterns such as request/response, request/multiple responses etc., can be created using SOAP by combining these one-way exchanges with features provided by an underlying protocol and/or application-specific information.) SOAP provides a framework by which application-specific information may be conveyed in an extensible manner and has nothing to do with the semantics of any application-specific data conveyed through its application.
  
• Some of its uses are RPC, and communicating messages with platform-independent content. It is also widely used for implementing web services.
  

DPM - The Business Architects @ Quadrobay