The Authorise-Capture model is used by some paymentmethods. For now, AfterPay is the only paymentmethod that supports (and requires) Authorise-Capture.
In Authorise-Capture, you first have to do an Authorise operation. If succesfull, it means the payment method guarantees that you can do a capture at a later time. When you do a capture (for example, when you ship the items) the money is actually debited from the consumer, and a capture results in a Transaction. Note that the details of the implementation of Authorise-Capture will differ per payment method.
Initiates a new authorisation and returns an object indicating success and the AuthorisationId needed to do the Capture.
Starts a capture on an open authorisation and returns status and TransactionId.
Cancels an open authorisation and returns status.