My 5 top favorite upgrades from HTML to HTML 5
1) HTML 5 has high-level audio and video support which was not a part of the version specifications in previous HTMLs.
2) SVG, canvas and other virtual vector graphics are supported in HTML5, whereas in HTML, using vector graphics was only possible by using it in conjunction with different technologies like Flash, VML, and Silver-light.
3) HTML5 uses web SQL databases, application cache for temporary storing data, meanwhile, in HTML, only browser cache could be utilized for this purpose.
5) HTML5 is not based on SGML, and that allows it to have improved parsing rules which provide enhanced compatibility.