An Open Room is open to anyone. Anyone can enter anytime without requesting for
permission.
A Limited Access Room can only be entered by members. Anyone wants to enter has to
send you, who is the owner of the room, request and you have the right to grant or deny
the permission. You could also choose who's going to be the member of the room from
your teammate list (if you have any teammates) if you selected this room type. (See List
of Teammates for details.)
A Private Group Room is one you create exclusively for a group of people who you
choose from your teammate list. It's invisible to non-members and no one can request to
enter.