Web 2 is the new look, programming of websites. for example Youtube is a web 2 website, digital point forums is a web 2. in fact if you have a wordpress website with the default theme that will be web 2, or other clean modern themes that depend mostly on CSS3 and HTML5. and to make a long story short go here: [video=youtube;Bc0oDIEbYFc]http://www.youtube.com/watch?v=Bc0oDIEbYFc[/video]
The definition of web 2.0 seems to be a netter of hype and marketing speak.The web 2.0 is an term referring to the ongoing transition to a full participatory web,with participating including both human and machine.Web 2.0 is typified by lightweight user interface popular favourite are AJAX and Macromedia Flex.
Web 2.0 are the latest website techniques which help in SEO to create back link and promote business services through web 2.0 websites. Wordpress, weebley, tumbler etc are web 2.0 sites.
Normally Web 2.0 are used to create linkwheel , 3/4 tier wheels and even linkpushing, this will pump all the SEO juice to your site.