You can choose from several different types of accounts when you add new users. Each type of account comes with different privileges:
An "administrator" has full access to the account with all permissions including account maintenance, users, billing information, and subscriptions.
A "power user" has similar permissions to an administrator except they can't edit or view subscriptions or other users and they do not have access to billing information.
A "user" is the most limited role. They can only view the account. They can't view subscriptions, other users on the account or access billing information.
The "no login" role essentially disables the user. They won't be able to log into the account.
For instructions on how to add a user, click here.