The legal owner of the business. Only one per business. Ownership transfer is a separate explicit flow.

What Owners can do

Everything Admin can do
Modify other owners (when transferring ownership)
Pay for and change the subscription
Delete the business

Owner-only actions

These are the things only the Owner can do - even Admins can't:

Transfer ownership to another member (the new Owner gets all rights, the old Owner becomes Admin).
Pay for the subscription or change the plan.
Delete the business - permanently removes the business and all its data.
Modify the Owner row in the staff list (everyone else sees the row as read-only).

How to become an Owner

Every business has exactly one Owner. The first person who creates the business is the initial Owner. The only way to change Owners is the explicit Transfer Ownership flow in business settings.

Best practice

Don't use the Owner account day-to-day. Create at least one Admin and use that for daily operations - the Owner account stays as a backstop. If something goes wrong with permissions, the Owner is always the one who can fix it.