I Have an XML question, please answer!

[naitsirhc26]

I was wondering, what is XML used for? Can I just use XHTML and XML and HTML would be taken care of? Please let me know. I am just learning this stuff, thank you very much!

[choster]

XML is a language (or family of languages) for describing and exchanging data between different systems. It does not replace HTML per se, although one kind of XML, XHTML, is designed specifically for use in marking up documents for delivery over the web.

While the basic text and images of your site would be delivered in XHTML, you might additionally provide an RSS [webmasterworld.com] feed, deliver multimedia using SMIL [webmasterworld.com], or access external systems using SOAP [webmasterworld.com], for three examples.

Some desktop applications you use may write XML files, although they do not explicitly say so. Your calendar program may understand xCal; QuickBooks writes qbXML, and Microsoft Office has a whole family of XML languages. In the corporate and academic worlds, XML has many specialized, heavy duty, non-web uses such as corporate financial reporting (XBRL), tagging Sumerian literature (ETCSL), and even facilitating environmentally friendly building construction (gbXML).