Social course activities encourage student-to-student interaction. Peer interaction is one of the most powerful learning tools that Moodle offers. It not only encourages learning, but also encourages exploration. This tool also makes courses more interesting because students can share their knowledge, which increases student participation and satisfaction. Peer sharing is part of the social constructionist approach to learning. Moodle embraces this approach. This chapter teaches you how to add communication activities to a course and how to make best use of them.