This specification defines the 5th major revision of the core language of the World Wide Web, HTML. In this version, new features are introduced to help Web application authors, new elements are introduced based on research into prevailing authoring practices, and special attention has been given to defining clear conformance criteria for user agents in an effort to improve interoperability.
Here's the W3C
Working Draft Here is a list of differences and some specific examples:
- New parsing rules oriented towards flexible parsing and compatibility
- New elements – section, video, progress, nav, meter, time, aside, canvas
- New Input attributes – date/time, email, url
- New attributes – ping, charset, async
- Global attributes (that can be applied for every element) – id, tabindex, repeat
- Deprecated elements dropped – center, font, strike
