Cancellation, reversal, and refund describe the same thing from the customer's point of view — "I got my money back" — but they're different operations, and the key difference is whether the charge was captured.
Cancellation
It happens before the charge is captured. The transaction is stopped and the money never leaves the buyer's account; at most, they'll see a temporary hold that their bank releases within a few days.
Reversal
It's the voiding of a recent authorization, usually on the same day. The bank undoes the transaction as if it had never existed. For the buyer, it may be invisible or show up as a charge that "disappears."
Refund
It happens after the payment was confirmed: the money is already on its way to your account, and you instruct that it be returned in full or in part. It creates a new transaction that is deducted from your balance and travels back to the original payment method.
Example
A customer accidentally pays $1,200 twice. The second charge is detected the same day: if it hasn't been captured yet, it's canceled or reversed and the customer doesn't see the duplicate charge on their statement. If it's detected a week later, a refund of the duplicate payment is the way to go.
What you should do
If you need to return money from a confirmed payment, follow How to issue a refund from the Conekta Panel.