This document provides an overview of social media. It defines social media as internet applications that allow users to create and share content. It notes some key statistics about major social platforms like Facebook, Twitter, and Digg. It then describes characteristics of social media channels like participation, openness, conversation and community. The document outlines basic forms of social media including social networks, blogs, content communities, and virtual worlds. It also provides brief explanations of how various social media platforms work. Finally, it suggests ways to engage with social media and lists some further reading on the topic.