The Administrator account is used by the owner, club manager or general manager of the club, and there is only one Administrator account given per account.
When you log in with the Administrator account, you can change settings on 'Staff Management', 'InBody Device Management' as well as the overall 'Settings' of the account, and the Payment page.
The sub-account (Staff account) is an account that can be used by the instructor, consultant, trainer, or staff of the place of use, and there may be multiple sub-accounts per place of use. When you log in with the sub-account (Staff account), you can do consultations with members based on their InBody data and also get 'assigned' for a specific member to use member management functions such as 'chat'.