Discussion Topics can be set up such that all students in the course offering can see and respond to all of the threads. On the other hand, a teacher can also set up a discussion topic such that all students see the topic, but they only see the responses of other students who are part of their same section. 

Your course can have multiple forums and topics, but you must create a forum before you can create a topic since all topics belong to forums.


How to Create a Discussion Forum

How to Create Discussion Topics Where Only Students in the Same Section See Threads

How to Restrict a Discussion Board Topic to One or More Sections

Return to Sections Setup.