Transaction
The diagram below describes Stash!'s transaction flow. One of the possible operations is pre-authorization which is used to reserve a certain amount of money in a request. After the transaction is pre-authorized, it is possible to execute a capture, the actual charging of the reserved amount, or to cancel a transaction by executing a reversal.
The other possibility of executing a payment is an authorization. It will charge the desired amount of money immediately. It is also possible to refund the money to the customer after the transaction is processed, after capture or authorization, by calling a refund.
You can find more information about the transaction operations in the links below: