Social media refers to online platforms that allow users to share content and engage in social interaction. The document discusses common types of social media like blogs, social networks, and photo sharing sites. It provides statistics showing that over half of internet users have joined a social network and 96% of millennials use social media. The document recommends ways to get involved with social media, such as listening, participating, relinquishing control, and engaging readers. It also suggests popular social media platforms to use, including Facebook, WordPress, Twitter, Picasa, SlideShare, and YouTube.