Only the account owner can edit the map. The account information can be shared at your discretion.
Anyone who has the url to can view the map if there is not a password on it.
Maps with the password are only visible to those who have the map url and the password.
The account owner can view or edit their maps anytime they are logged in.
Anyone with the map edit url can modify the map.
Anyone with the map url can view the map.