What is the foundational technology for Web services?

The foundational technology for Web services is XML. XML, or Extensible Markup Language, serves as a versatile and structured way to encode data, making it easy for various systems to communicate over the internet. It provides a standard format that can be understood across different programming languages and platforms, which is essential for web services that aim to function interactively among diverse systems.

Web services utilize XML to define message formats, allowing data interchange to be platform-independent and language-agnostic. This fundamental aspect enables diverse applications and services to work together seamlessly. Although other technologies mentioned—such as SOAP, UDDI, and HTML—play vital roles in the implementation and functionality of web services, XML is the core technology that underpins data structuring and exchange, making it the foundational element.