What does "XML" stand for?

“What does XML stand for?” — XML stands for Extensible Markup Language. It is a text-based markup language and file format designed to store, structure, transmit, and reconstruct data.

XML grew out of SGML, an older standard for defining document markup. Work on XML began at the World Wide Web Consortium in 1996, and XML 1.0 became a W3C Recommendation on February 10, 1998. Its designers aimed for a simpler, more practical format that could work across different systems and support many human languages through Unicode.

XML uses custom tags to describe the meaning and structure of information. For example, tags can identify a title, date, or price rather than merely controlling how text looks on a page. This makes XML both human-readable and machine-readable, although JSON is now more common for many web APIs.

The “X” means “Extensible”: users can define vocabularies suited to particular fields. XML is not the same as HTML, which has a predefined set of tags focused primarily on displaying web documents.