In the community module, you can join different groups and pages.

All our groups are private, i.e. the posts in the shares are not public, only the members of the group can see them, and they are invisible to search engines.

Here you can check the privacy settings for that group.

Essentially it's like Facebook, you can add friends, join groups, have your own newsfeed that you can configure who can see you, and configure your shares in the same way.

There is one major difference, everything is private, there is no strict moderation, you can share links, files, ask for books, and exchange other useful information.