The customer owner role is the highest access level within the Client Cloud application.
This user can edit any customer level options including: create, edit and delete all clients, see closed cases, create, edit, and delete users, and edit customer settings (contact info, mileage rate).
This user type still needs to be assigned a Client Cloud (standard or read only) and an Client Invoice (invoice reviewer, employee/vendor, or invoice reader) role to properly access both applications.