The rapid adoption of social network sites by teenagers in the United States and in many
other countries around the world raises some important questions. Why do teenagers flock
to these sites? What are they expressing on them? How do these sites fit into their lives?
What are they learning from their participation? Are these online activities like face-to-face
friendships or are they different, or complementary? The goal of this chapter is to address
these questions and explore their implications for youth identities. While particular systems
may come and go, how youth engage through social network sites today provides long-lasting
insights into identity formation, status negotiation, and peer-to-peer sociality.