Social media are applications that have a networking dimension at the heart of their use. They attract language learners, teachers and providers for different reasons, although they are a controversial issue in language education as we lack evidence whether and how they promote language learning. This book studies the impact of networking with the social media on language learning, through a collection of chapters offering theoretical perspectives and empirical studies of learner experiences in a wide range of networking settings, illustrating through a variety of teaching as well as research methodologies. Through focusing on communities and socialization, together the editors and contributors help to identify priority issues (such as identity and community-building) that need attention if today's social media culture is to work to the benefit of language learners.