Extensible Markup Language is abbreviated to XML. The World Wide Web Consortium created it. Coding has become popular, and it uses XML as its language. Extensible HyperText Markup Language is also known as simply XHTML. It is the combination of XML and HTML. XML transfers data. It transfers data between the hard drive and a few other things, including the operating systems and applications.
If you want a language system that is cleaner and stronger than it is best to use the XHTML compared to the XML because it is better. If you want something that is not limiting, then it would be best to use XML because XML can be used in multiple applications compared to XHTML.