What is Web 2.0

Note: The cloud-map picture above (constructed by Luca Cremonini on December 25, 2006, for railsonwave.com) has been recreated in svg format from the image of Markus Angermeier and was improved with links to Wikipedia sources at http://commons.wikimedia.org/wiki/File:Web_2.0_Map.svg

Web 2.0 refers to a  new generation of web technologies that has enabled people to use the web, create content and easily publish online, to interact with one another, and to share both online and offline resources.