You may be interested in this posting from the W3C which covers the differences between HTML and HTML5. Topics covered...encoding changes, doctype declaration, obsolete elements, new elements, attribute changes, etc.
http://www.w3.org/TR/html5-diff/
JorgeM
Industrious Poster
4,018 posts since Dec 2011
Reputation Points: 297
Solved Threads: 548
Skill Endorsements: 115
html 5 is a great advancement in the html spec.If you want to develop a web appllication, a website that goes beyond presentation use it.Has great support for css 3.Also customised for developing on mobile devices in conjunction with css 3 and javascript- web apps for the iphone etc.Supported by almost all major browsers and all the big guys(facebook,google etc) are using it.Bottomline you have to know it.Switch Now pedro!!kidding.....
Sarama2030
Junior Poster in Training
79 posts since May 2009
Reputation Points: 10
Solved Threads: 4
Skill Endorsements: 0
If you are considering deploying a new website, you should start to use the HTML5 Doctype. This doesnt meant that you have to include new HTML5 elements that some browsers do not support yet. As newer browser versions appear, more support for HTML5 elements will be available.
JorgeM
Industrious Poster
4,018 posts since Dec 2011
Reputation Points: 297
Solved Threads: 548
Skill Endorsements: 115
HTML 5 is the advanced verision version of HTML i.e it is the 5th verision of HTML standard. Html 5 differs from HTML in its structure.
Other additional functionalities provided by HTML 5 are:
-Context Menus
-Async attribute
-<details> tag
-<datagrid> tag
-<menu> tag
-<command> tag
princysharma90
Junior Poster in Training
87 posts since Jul 2012
Reputation Points: -2
Solved Threads: 1
Skill Endorsements: 0