The Simple Object Access Protocol (SOAP) is a simple and light-weight protocol for exchanging messages. SOAP is an extensible and decentralized framework that can work over multiple transport protocols. Remote procedure calls can be modeled as an interaction of several SOAP messages. SOAP is one of the enabling protocols for Web services.
SOAP can be run on top of all the Internet Protocols, but HTTP is the most common and the only one standardized by the W3C. SOAP is based on XML. It's design follows the "Head-Body" Pattern, not unlike HTML. The head contains meta-information[?] like information for routing, security and transactions. The body transports the main information.
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