The refund is sent to the payment service provider. In some payment service providers you can still cancel the refund at this stage.
The refund was succesful and has been settled to your customer.
The refund has failed. For example due to a closed bank or card. The payment service provider will return the amount to your account balance.
The refund was canceled.
The refund is queued to be processed. A refund might be in this status when your account balance at the payment provider is not sufficient to initiate the refund at this time.
The refund is being processed.