SOAP: Simple Object Access Protocol
There are several different types of messaging patterns in SOAP, but by far the most common is the Remote Procedure Call (RPC) pattern, in which one network node (the client) sends a request message to another node (the server), and the server immediately sends a response message to the client. SOAP is the successor of XML-RPC.XML and HTTP are two such minimal technologies. The Simple Object Access Protocol (SOAP) defines the use of XML and HTTP to access services, objects, and servers in a platform-independent manner. SOAP is a protocol that acts as the glue between heterogeneous software components. If developer can agree on HTTP and XML, SOAP offers a mechanism for bridging competing technologies in a standard way. The main goal of SOAP is to facilitate interoperability.