Under the Discussions tab, everyone involved in a class is welcome and able to generate new topics, as well as respond to existing topics.
The instructor might post bonus materials here that are less formal or simply different in form or nature from a major lecture. The class facilitator might post a breakdown of assigned peer review groups, if the instructor has opted to make small group assignments.
You and your fellow classmates may generate new discussion topics, as well, whether directly related to major class topics or more tangential and in the spirit of community building.
Once the class has officially ended, the class discussion board is a great place to keep up with other students to share feedback and successes.