xml vs xhtml

Ok, this might be kind-of-a-duh-question for you guys, but I will ask it anyway.

I've been going through tutorials online as well reading several books on the subject of xml and although I find it interresting, I can't seem to find any real use for it when designing an ordinary webpage that only holds text, images and hyperlinks. I understand that xml must be a wonderful thing to have when you have the need to define everyting in a webpage, but is there really a need for it if you only plan to provide the web with a "normal" webpage?

I don't think XML was ever intended as a replacement for basic HTML, nor was it intended to be used on every web page for basic, "normal" sites. XHTML allows you to create your web page using the HTML you know, while enabling you to encorporate XML if you need to, but only if you need to. If you were to build your site with XHTML, and later you needed to use XML, you would be able to do so easily. But just b/c you can use XML, doesn't mean you should. XML is used to describe data. If you don't have data to describe (meaning you simply want to layout your data), then don't use XML.

I should note that I'm no expert in XML. I just started learning it a couple of weeks ago.

The idea behind XML is to separate the display and layout elements from the data. This allows you to take the raw data of a page (XML) and display it in a multiple of ways using technologies such as XSLT, ASP, CSS, etc.

The idea behind XHTML is to make it conform more to the principles of XML like making sure every open element is closed. Most browsers do not actually have the support for strict XHTML because of the different conventions that are required for tagging.

I would say if you are creating a page that you don't intend to make wide sweeping changes to, stick with (X)HTML.

XML is a great technology for a dynamic frequently changing website.

Can you show some examples of what you're talking about here?

Just to clarify, by "strict" XHTML, I mean XHTML built on the "strict" XHTML DTD as opposed to the "transitional" form of the DTD. Last time I tried to implement strict XHTML (and maybe things have changed with the most recent browser releases) browers had trouble especially with leaf elements that are not required in HTML such as <br /> and <p /> and closing single elements where the closing element isn't required such as <script /> <meta /> etc.

Plus with strict XHTML, more of the display and layout has been removed from the tags which requires your browser to more completely support CSS.

Unless you are supporting only one browser, you may run into compatibility issues, especially with older browsers.