Right now there are two topic types for “Questions” and “Discussions” and the difference between them isn’t fully articulated by the software. Questions are intended for topics where you have a question that you want an answer to. Once having the “right” answer these topics will be less visible. Discussions are open-ended and won’t close or have a specific answer selected.
At this time the differences are not very clear, but we are going to build auto-closing for the questions and the question topic type is not going to support open ended discussion well.
So if you just want one right answer to a question that has an objective answer use the questions topic type. If you want to discuss things and get multiple opinions and viewpoints use the discussion topic type, even if your discussion is started by a question.