What is the difference between a preferred number and a mobile number?

A preferred number is the number dialed when a Voalte One user calls a Voalte Me user (or a Voalte Messenger user who has calling enabled).

A mobile number is used for Voalte Me Enrollment SMS. 

These two fields will typically be the same number. Having separate fields allows hospitals to leverage the Enrollment SMS (mobile number) without forcing the user's account to be callable (preferred number).