The emergence of Web services is transforming traditional enterprises. However, the industry hype surrounding these technologies obscures the understanding of their impact and implications to enterprises. Here the authors take the "big picture" perspective, offering a thorough understanding of the concepts behind Web service technologies: the challenges and opportunities they present, how they fit into the enterprise stack, how they relate to the business and IT layers of the enterprise, as well as the existing and emerging standards and their relevance. This professional reference is a guide for computing professionals, academics, students and researchers, helping them learn about the important concepts behind the Web services paradigm and its impact on the enterprise. In addition, the text instructs professionals, business managers and analysts on how to use Web services in the context of traditional application, system and network management.