difference between html and xml?

[benjorgensen]

I keep hearing people referring to the XML someday taking over HTML but I don't understand the difference. Could someone illuminate me? Thanks.

[doctorgonzo]

They are both markup languages. However, XML is extensible (hence eXtensible Markup Language), meaning you can define your own markup tags to be whatever you want. HTML has a more or less fixed set up markup tags for formatting displays only (like header tags, table tags, adn the like). XML tags define data, not presentation, but you can manipulate that data for presentation purposes. XML is much more flexible and can be used for just about any data, not just web pages.

[aym]

To add more info, XHTML is an XML compatible version of HTML.