Community Functionality
Communities allow collaboration around specific projects and topics, combining SharePoint list and library functionality with social streams in one place.
Create public communities for open sharing across the company or private communities for select groups. Administrative reporting allows tracking of activity within the community.
Note on permissions inheritance
Converting an existing site into a community
Creating and setting up a brand new public community (site-level)
Creating and setting up a brand new private community (site-level)
Creating and setting up a brand new community (site collection level)
Setting Community Followers Using the Default Members Group
Automatically Subscribing Members to Notifications
Setting Community Followers Using SharePoint Audiences
Setting Which Libraries May be Used to Store Stream Attachments
Follow / Stop Following Integration Point
Granting Curator and Expert Roles
Setting the Notification Email Timing