This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book examines how social media features in established and emerging forms of civic engagement and participation in contemporary Western democratic societies within a globalising world. It also examines contemporary kinds of civic engagement and participation that include more traditional forms of engagement, such as community action groups and campaigning groups using social media. The book reviews how engagement and participation are being organised by social movements, individual appeals, campaigning networks and protest movements. It explores how the characteristics of social media are interacting with lived political culture — that is, how people engage and participate in civic life. Social media may also be an important feature in communicative civic-ness, since both government and citizens have to find better ways to understand and communicate with each other.