Discussions are made for brief questions or ideas you want the community to see. Usually you make a discussion post when you want to get quick feedback or know the answer to something. You can specifically make a discussion a question, such as when you have a specific question that another person probably has the answer to. That will help ensure that your question gets the kind of attention it needs.
When a discussion thread collects information that you want to preserve for other uses, you can save the discussion as a document. For more information, see How do I convert a discussion thread to a document?
With discussions you can:
To start a new discussion post, click New > Discussion, select the space you want the discussion to live in, then click Create New Discussion.