Each topic will most likely cover some large area of discussion, like a chapter from a book or a particular concept. Each topic has a page of its own on which you will find a Topic Message, which introduces that part of the conference, and then lists a series of conversations. Anyone in the conference can start a conversation or reply to a conversation. Then, other people who stop by that Topic Page can see your message and reply to it as they choose. Fair Witnesses are in charge of setting up the conference, adding users to the access list so they can view the conference, creating topics of discussion, and regulating the conversations that take place.
Participants are the students.
Their 'job' is to check by regularly for new information and to take part in the conversations.