Social media refers to online platforms that allow users to create and share content with others. It started as text but now includes audio and video. Key characteristics include participation through comments, ratings, and forums; openness through public sharing and commenting; two-way conversations between many users rather than one-way broadcasts; formation of online communities around common interests; and connectivity through links between sites and people. Popular social media platforms include blogs, social networking sites like Facebook, microblogs like Twitter, forums, wikis, and podcasts. Social media is having a fundamental impact on thoughts and behaviors and is shifting power away from traditional media elites by democratizing communications.