If GateKeeper:2.0 fraud screening is enabled on your account, each transaction will be allocated a score based on its risk profile.
You can view this information for any transaction by viewing the order, then clicking the Show Payment Details button.
The 'Risk Review' shows you what the fraud screening determines for the order.
For transactions requiring review, it will only be possible to invoice and complete the transaction once the transaction has been approved in Gatekeeper.
If a transaction is rejected in Gatekeeper, this will update the decision information in Magento for the order.
Refer to the Gatekeeper user manual for more information.