A community can be set up by any user to provide a space to share documents, have online discussion, etc. It can be set up as protected and only accessed by authenticated users and further can be configured to require registration or not, etc. There are three types of communities which can be used for different purposes. The three types are: community, course website, and learning module. More detail is in the Community>Types help section. All communities can be configured to include features like announcements, discussion boards, document sharing, quizzes, events, polling, etc.