Markup language
A markup language is a set of tags that describe the content of a document.  The most common markup languages today is [[HTML]] a markup language is not a programming language, hence it is a misnomer to 'code' HTML.  [[XML]] has introduced extensibility into HTML called [[XHTML]].  This new more versatile language can incorporate many types of media, other than plain text; and web browsers are constantly adding more support for [[W3C]] languages such as [[SVG]] and [[XSLT]].   XML has strict rules that can increase the learning curve for a person new to XML-based markup.  However once the rules are understood, it leads to more consistent and error-free markup which allows more devices to process the information correctly.
      