As mentioned in the documentation here, there are a number of different payment statuses. Those include,
PaymentInitiationRequestPending is the default status of all created payments. Payments will remain in a PENDING state unless cancelled via the API directly - more info here.
PaymentInitiationRequestCancelled is the status of a payment after the payment has been cancelled via the API - more info here.This status is final and cannot change.
PaymentInitiationRequestCompleted is the status of a completed payment which has been successfully actioned by the user. This status is final and cannot change.