What is the difference between Payment Notification URL, Finish Redirect URL, Unfinish Redirect URL, and Error URL?

Payment Notification URL is the merchant’s endpoint URL where Midtrans’ notification engine will send a success or failure HTTP notification.

Finish Redirect URL refers to webpage that will be seen by customers after they successfully completed their transactions. Unfinish Redirect URL refers to the webpage that the customer will see if he or she does not proceed with the transaction. Lastly, Error Redirect URL refers to the webpage the customer will see if the transaction fails.