XML... please explain

Call me ignorant or dumb, but not lazy. I have tried to read-up on XML has much as I can comprehend, but the idea still confuses me.

I had always considered XML to be used mainly as a data transport... sharing information in a structured way from location A to location B (ie. different companies or platforms).

It seems, from what I now hear / see, that my understanding of it was completely wrong. People are using it to run their websites, as a means of storage, pretty much everything -- all the hype has made it out to be the end-all-be-all. "XML will do away with databases", "XML has replaced html", etc. I thought databases still did a great job of managing content (they're secure and fast), and HTML is a fine markup (especially with the XHTML recommendation - I know this is a mix in which XML brings proper organization and structure to HTML). But perhaps I'm just old school. It really reminds me of the craze created by OOP -- people even mentioned making toasters with OOP!

Can someone explain XML to me? ... or post a location where I can read past the hype and learn when it is most effectively used and for what.

Thanks

Behind all the hype XML is simply this...

<witch>
<hair>black</hair>
<eyes>brown</eyes>
<teeth>brown and crooked</teeth>
<hat>black and pointed</hat>
</witch>

Nothing to it. The next step is creating a Document Type Definition or Xtensible Style Sheet to apply to it
that would render to the screen our witch. Should you change the eye color to blue then it would be compensated for and she would render with blue eyes instead. Yes it could be done in other ways, but XML allows for human edited XML to become something special fast. Scalable Vector Graphics are a good example of this.

The thing about web sites done with XML is that they're able to present the same data in many different fashions. They can also be edited by people who don't have a clue about the HTML syntax because you are separating data from layout.

An example would be this:

By Course

and

By Class

Okay, don't worry about the content but what these do is parse the kell02be.xml file to display two different outputs from the same file. Therefore half the web space is needed. This is just one of the ways I've used XML.