What does XML stand for?
eXtensible Markup Language: some more precision, in reverse order:
XML is a language to define other languages: it is in fact a
This informs us that the structuring elements of that language will be
tags, like used in HTML: a tag name enclosed in brackets: <ATag>.
XML is not a language (which is by definition fixed) but a
meta-language. XML is a set of rules, that a language must respect in
order to be XML conformant. Therefore you can define your own mark-up
language, and make it to evolve at your envy.