Payoff is the total amount a player receives back from a winning bet, spin or hand. It is a gross figure: it usually includes the original stake as well as the winnings, so on its own it says nothing about profit. A $999 stake that returns $1,000 is a $1,000 payoff but only $1 of net winnings.
Payout tables make the distinction clear through their wording. Odds quoted as “5 to 1” return the stake plus five units, while “5 for 1” returns five units in total, stake included, which is the same as 4 to 1. For operators, consistent payoff wording across game rules, bet slips and transaction histories prevents disputes and keeps the reporting of stakes, wins and gross gaming revenue clean.