Well i have a question for you. When you create a group you should put the type of group: pubblic, moderated or invite only.

who can explain me the difference about that?
thx

Public : Anyone can join, and the threads/posts are visible to anyone.
Moderated : I don't really know, never tried
Invite-only : Only people you invite are able to join your social group. Other members can't see the group's threads/posts.

Anyway, you can change the type of your group once you have created it.

Thanks but the moderated style interesting me. what the moderated mean? somebody help me

When you put a social group as moderated, people can request to join, and post new threads/posts in the group even if they are pending.

The group keeper needs to approve these members before they can be seen in the member's list.

Thanks