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HTML

Posted by Demian Arend
Demian Arend
3,386 Points

What makes XHTML XHTML?

I've recently gone into an old site that I built a year ago using Microsoft Expression Web which writes in XHTML. Now that I know CSS and HTML much better thanks to Treehouse I've been going in and rearranging the code and sprucing up the site. But I can't really see what's different between what I've been taught as HTML (HTML 4 with Treehouse) and the XHTML that the old program wrote.

Other than this line which starts at the top of each page:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml">

I can't see what on earth is different. Can somebody explain?

Thanks, Demian

1 Answer

James Barnett
James Barnett
39,199 Points

There isn't a difference really XHTML is flavor of HTML that is also valid XML which is a more generic markup language that has stricter syntax.

For a more detailed & technical explaination, a quote from the wikipedia page

While HTML (prior to HTML5) was defined as an application of Standard Generalized Markup Language (SGML), a very flexible markup language framework, XHTML is an application of XML, a more restrictive subset of SGML. Because XHTML documents need to be well-formed, they can be parsed using standard XML parsers—unlike HTML, which requires a lenient HTML-specific parser.

You can also check out this: http://www.dummies.com/how-to/content/the-relationship-between-html5-and-xhtml.html

Scott Magdalein
Scott Magdalein
2,406 Points

Excellent answer.

Demian Arend
Demian Arend
3,386 Points

Thanks, James. Interesting answer. I haven't checked the link yet but will. Still your brief explanation gives me some insight into a question that had me a little bit mystified. :)