Money
Wet rate
An hourly aircraft rate with fuel included. The operator absorbs fuel price swings; the renter gets one predictable number.
In practice
Wet rates are the norm for rentals and flight training because they keep the transaction simple: fly the hour, pay the rate. The operator carries the risk that fuel prices rise between rate reviews, which is why wet rates are re-examined whenever fuel moves. Clubs choosing between wet and dry billing are really choosing who holds the fuel-price risk and how often they want to argue about it.
See it with your own aircraft.
Add your aircraft and your rates, then see the schedule, the squawks, and the ledger all work off one record. No card required.