This video shows you the the difference between older Html and Xhtml documents and the new Html 5 documents.
It also gives you a brief introduction of new Html5 elements and how they are are implemented.
This video will show you how the Html 5 is more powerful and yet easy to use that (X)Html.
Link to my Html 5 forms tutorials (9 videos)
Link to my Css text cheatcodes (30 videos)