HTML 5 is a bit like Flash, if that means anything to you. The problem with Flash is that Apple devices such as their desktops, laptops and mobile IPAD and IPHONE cannot display Flash nor can the Windows phone.
Flash was less easily indexed by search engines and lastly, a little expensive to build.
So, now HTML 5 is here, all up to date browsers are able to display it so, as they say, bring it on.
Gallery of fun HTML 5 websites