An authorised payment can be either captured or canceled. If a payment has been already captured, it can be also refunded later. Capture, cancel, and refund actions are called modifications, since they modify the state of a payment.
Modifications can be done either manually (through the Customer Area interface), or automatically (using the Adyen payments platform API). If an API call is made, the merchant receives an acknowledgement in the response. After Adyen processes the payment modification, Adyen sends the result asynchronously through notifications.