A general term for an online "bulletin board" where you can leave messages and see responses to messages you have left. Discussion groups generally keep a history of comments made, and often support attachments for messages.
An area online focused on a specific topic where users can read and add or "post" comments ("post" in the sense of posting something on a bulletin board). You can find discussion groups, also referred to as "discussion boards," for almost any topic. See also "Newsgroups."
A location on a web site where people with different backgrounds (product users, employees at public companies, those in the financial community) gather to share their ideas about investing and personal finance (or any other topic).