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, a merchant synchronously receives a response from the Adyen payments platform with the modification result. At the same time, a merchant also receives notifications every time a payment's state is changed.