In this chapter we started by taking a look at the role SOAP plays in a Web services architecture. We looked at what a SOAP message is and how it can be used to wrap XML content for transportation between two parties. The content is separated from the underlying transport, and the parties processing that message can be written in any coding language. SOAP represents a simple yet powerful abstraction for realizing a cross-platform and loosely coupled architecture.

An enterprise-level app requires more sophisticated features that those offered by SOAP alone. In subsequent chapters, we examine how to exploit SOAP's extensible nature to address these needs. In , we discuss a more complex business collaboration scheme offered by ebXML, using SOAP. In , we look at how transactions can be layered on top of SOAP messages. In , we deal with security issues and discuss how SOAP can be extended to address these concerns.

In this chapter, we have intentionally not covered every minor detail surrounding SOAP. Our intention was to present the reader with just enough depth to establish the fundamental concepts. In subsequent chapters, we discuss pertinent details where the concepts are applicable. For example, covers the pros and cons of RPC- versus document-style communication, and covers messaging with SOAP.