Lecture 10 introduces web services and service-oriented architecture (SOA) as foundational technologies that enable cloud computing. The lecture explains what web services are, why they are XML-based, and how they allow applications from different platforms and vendors to communicate using standardized messaging protocols. It traces the evolution of web services from distributed computing and electronic data interchange (EDI), highlighting how web services overcome limitations such as interoperability issues, firewall traversal, and system complexity. The lecture discusses the core web services stack—XML, SOAP, WSDL, and UDDI—and explains how these technologies work together to support service publishing, discovery, and binding. It also introduces the SOA model involving service providers, consumers, and registries, emphasizing the publish–find–bind interaction pattern. Finally, the lecture connects SOA directly to cloud computing, showing how web services act as the primary building blocks for IaaS, PaaS, SaaS, and XaaS models.
