Answer:
True. However, those are not two types of discussion groups, but only one.
Step-by-step explanation:
Online forums possess a tree-like structure. A forum can contain several sub-forums discussing topics somehow related to the original subject.
Forum conversations differ from chat, because messages are typically longer, and are stored for longer. Each conversation in an online forum is called a "thread".
A bulletin board is a type of online forum in which its participants post questions to a related topic and other members try to provide the answer to that question. The answer is open to discussion and other members are free to intervene and correct the answer, if needed. A moderator is usually present, to ensure ethical behaviour and encourage the participants.