You can create a public or private group depend on the privacy of members inside your group. In this guide, we will explain to you the difference between public and private group
Public group: Content of the public groups will show at “Explore” tab in group home page. All users in your site can view updates from public groups at “Expore” tab and then can join without approval from owner/admin of the group.
You can change public group to private group whenever you need.
Private group: can’t see updates from this type of group at “Explore” tab but you can find it at “All groups”. If you want to join, you have to wait for admin/owner of the group to review and approve.
Can’t change private group to public group.