Everyone covered under an Account Owner’s umbrella will appear on his or her main Admin Dashboard. There are three types of users that can be added to an account: Account Managers, Account Users, and Project Users.
Account Managers can create/access/edit any project covered by the Owner’s account. The projects that they create are automatically covered under the account’s umbrella. They can also invite new Account Managers and Account Users.
Account Users can only access/edit their own projects. The projects that Account Users create are automatically covered under the account’s umbrella and they will be able to invite Project Users to each of those.
Project Users are users invited to individual projects covered by the Owner’s account. While they are financially covered by the account, the projects that they create are not. Project Users will be designated as either Project Admins, Project Members, or Project Followers. Their unique permissions are described in detail here.