Simple Object Access Protocol (SOAP)
The official definition, found in the most recent SOAP 1.2 specification, "SOAP is a lightweight protocol intended for exchanging structured information in a decentralized, distributed environment. SOAP uses XML technologies to define an extensible messaging framework, which provides a message construct that can be exchanged over a variety of underlying protocols. The framework has been designed to be independent of any particular programming model and other implementation specific semantics." This definition really gets to the heart of what SOAP. SOAP defines a way to move XML messages from point A to point B (see Figure below). It does this by providing an XML-based messaging framework that is
1) extensible,
2) usable over a variety of underlying networking protocols, and
3) independent of programming models.[1]
source: [1]
See Also
Enterprise Service Bus (ESB)
Service Oriented Architecture (SOA)
Enterprise Integration
Enterprise Architecture