The type of usergroup controls primarily controls how the system expects the group to receive information. Almost all usergroups will be of the type user which means it is a group created by a user for others on the site to join and share information.

The other setting, only available to administrators is automatic which refers to a group that members can join but will receive information from the modules on the site automatically and may be removed by the system at some point depending on the module controlling the group. Automatic Groups are planned for future implementation