What is the different between HTML and xHTML?

Answer 1

XHTML opening tags are 'closed' again instantly (although they are closed again further down) e.g. .

The difference between HTML, and XHTML is that XHTML is XML and HTML combined. XHTML is the strict version of HTML.

Here is a script with XHTML:

"http://WWW.W3C.Org/TR/Xhtml1/Xhtml1-Frameset.dtd" />

Mark Elliot Zuckerberg (born May 14, 1984) is an American software developer and internet entrepreneur. He is best known for creating the social networking site Facebook, of which he is chief executive and president. It was co-founded as a private company in 2004 by Zuckerberg and classmates Dustin Moskovitz, Eduardo Saverin, and Chris Hughes while they were students at Harvard University. In 2010, Zuckerberg was named Time magazine's Person of the Year.

and now with HTML :

Mark Elliot Zuckerberg (born May 14, 1984) is an American software developer and Internet entrepreneur. He is best known for creating the social networking site Facebook, of which he is chief executive and president. It was co-founded as a private company in 2004 by Zuckerberg and classmates Dustin Moskovitz, Eduardo Saverin, and Chris Hughes while they were students at Harvard University. In 2010, Zuckerberg was named Time magazine's Person of the Year.

notice a difference?

EDIT: The newer answer actually contains CSS. This is something separate. XHTML is just a newer, improved version of HTML.

Answer 2

There are 4 main differences between HTML and XHTML.

1. In XHTML, all elements must be lowercase. In HTML, it's perfectly legal to use caps in your tags, but in XHTML all tags, elements, and attributes MUST be lowercase.
2. All elements must have a closing tag in XHTML. If you have an empty element that doesn't have a closing tag in HTML (such as or
   ), you close it in XHTML by adding a forward slash to the end (like or
   ).
3. All XHTML elements must be properly nested. In HTML, you can get away with this:

   This is some text

   You can't do this in XHTML, as tags must be closed in the inverse order they were opened. In order to be valid XHTML, the above example would have to be:

   This is some text

4. The document must be properly nested. In other words, the page should start with the opening HTML tag and end within the closing HTML tag. The head information should be between the opening and closing HEAD tags, and the page content needs to be properly nested within the BODY tag.