Extensible Markup Language
A markup language that facilitates the transport, creation, retrieval and storage of documents. Similar to HTML, XML uses tags to describe the contents of a web page or file. XML describes content of a web page in terms of the data that is being produced, potentially creating automatic processing of data in ways that may require attention for privacy issues, unlike HTML, which describes the content of a web page in terms of how it should be displayed.
Reference(s) in IAPP Certification Textbooks: F116