XML is a way of formatting data for structured retrieval using a tag-based system. Think "objects". It looks rather like this:
Code:
<myObject anAttribute="aValue">
<myThing>
<length units="xx">23</length>
</myThing>
<myThing>
<length units="yy">15</length>
</myThing>
</myObject> HTML is a collection of specific tags which have well-known and defined roles. It is also not as rigid as XML.
XHTML is a combo of them both. It's basically HTML with XML structure rules.
XML is a way of formatting data for structured retrieval. Think "objects".
HTML is a c using us