What is the difference between a preauthorized transfer and a draft for Reg D purposes?

From the Glossary Section of the Instructions for the FR2900:
DRAFT: An instrument signed by the drawer ordering the payment of a certain sum of money on demand to the order of a specified person or bearer.
PREAUTHORIZED TRANSFER Any arrangement by the reporting institution to pay a third party from the account of a depositor upon written or oral instruction (including an order received through an automated clearing house (ACH)), or any arrangement by the reporting institution to pay a third party from the account of the depositor at a predetermined time or on a fixed schedule.