All communities have different levels of privacy and access settings, which are decided by the host of the community.
Each community have different levels of privacy settings, which are:
1/ Public, where the community is visible to all users.
This means that all users will be able to see the posts and conversations going on in the community, but only card holders will be able to interact with other card holders in the community.
2/ Private, where info is public and searchable.
When a community is private, users that do not have access to the community will still be able to see the post pinned to top, but not the other posts. All users can find the community with the search button.
3/ Hidden, where all info is disclosed and not searchable
The only way to get access to a hidden community is by obtaining a Card. A hidden community can't be found with the search button by the public.
Besides privacy settings, hosts also have the following options to manage members of their community:
If the community is a private community or a hidden community, Card Holders have to request "Permission" from Card Creator to join the community.
Hosts can grand specific cards access, but not others.