SOAP

Like http is text based protocol having header and body…in similar way soap is protocol that define data in xml….SOAP defines the XML-based protocol for exchange of information in a distributed environment, specifying the envelope structure, encoding rules, and a convention for representing remote procedure calls and responses. So, SOAP, originally defined as Simple Object Access Protocol, is a protocol specification for exchanging structured information in the implementation of Web Services in computer networks. It relies on Extensible Markup Language (XML) as its message format and usually relies on other Application Layer protocols, most notably Remote Procedure Call (RPC) and HTTP for message negotiation and transmission

JAX-RPC provides a Java API for developers to invoke remote procedure calls, by abstracting and hiding the low-level SOAP semantics associated with RPC from applications.