HTML5 and CSS3
Currently HTML4 and CSS2 (and Flash) are the universal standard. HTML is the program presented to your browser. CSS is the program that tell your browser where to place everything, sizes of fonts and pictures, colors, etc. (Some websites are written in PHP and ASP language, however those languages are translated into HTML by the servers on which they reside before being sent over the internet to your computer.)
Do to security concerns Flash movies and animation will be phased out when HTML5 is fully implemented which some think may be around 2012. Internet browser are proprietary and cannot use the same coding so, they do handle the display of webpages somewhat differently from brand to brand. While smartphone and tablet carry browsers with familiar brand names, they are not the same browser program found in the desktop or laptop computer.
Apple jumped the gun on not supporting flash on their smartphones and tablets and have browsers that implement many of the HTML5 and CSS3 features being developed. Likewise Google’s Android has limited Flash support. My sites instead of Flash video use HTML5 commands which are a lot simpler to write. However, all the major browser do not support the HTML5 video command, so I have to add a special program to my sites to activate the proposed video commands. And interesting demonstration of CSS3 can be found at http://css3.digmedpre.com.