This document reviews literature on how and why people participate in online learning communities. It examines different types of engagement, including theoretical models that describe stages of involvement from peripheral to central participation. Motivations for participation are explored, such as the desire for recognition, connection, and helping others. Stages of participation in online learning are presented, ranging from initial socialization to full engagement. Finally, optimizing online environments for learning is discussed, focusing on reducing distances between participants and increasing social presence.