In this review of research, various aspects of collaboration are discussed to understand more completely the phenomenon of jointly constructed activity in pedagogical contexts. This chapter presents the parameter for collaborations, differentiates collaboration from interaction, and reviews studies organized into three themes: collaboration and community, collaboration and language development, and collaboration and identity. Concepts taken from sociocultural theory provide an overarching explanatory framework of learning in the collaborative setting. These concepts include goal-directed activity, human relations, mediation, history, and culture. Consideration for emergent directions for research on collaboration and language learning are presented.