Members (labeled Members in the left menu, under My Subscription) let the primary account holder create linked sub-accounts — e.g. one per family member — each with their own diet preferences and their own meal selections on the shared subscription, while the primary holder keeps control of billing and permissions. It's only usable by the primary account (a member login can't create or manage members of its own) and requires the business to have the Account Members module or be on the Base/Pro/Enterprise plan.