Web 2.0 refers to next generation internet-based services that emphasize online collaboration and sharing among users. It is characterized by services that allow users to interact and collaborate with each other in a social media dialogue as creators of user-generated content in a virtual community, in contrast to websites where users are limited to the passive viewing of content. Key elements include web applications that enable collaboration and sharing, content syndication via RSS/Atom feeds, and APIs that allow loose integration between sites.