Microsoft Dynamics CRM 2013 introduces Access Teams. Access Teams work in a simlar way to Teams in earlier versions for sharing but Access Teams cannot own records or be assigned security roles.
Access Teams are created in Settings | Administration | Teams. Teams that can own records are referred to as Owner Teams. The Team entity is used for both Access Teams and Owner Teams; the Team Type field determines the type.
An Owner Team can be converted to an Access Team but not the other way round.
Access Teams provide a more scalable approach than Owner Teams for sharing.
But of even more interest are Access Team Templates where you predefine the sharing permissions for an entity. ………… more to add here.