When you spin an online slot, the RTP tells you the average payout you can...

https://mag-wiki.win/index.php/Why_Do_Slot_Bonuses_Have_Wagering_Requirements%3F

When you spin an online slot, the RTP tells you the average payout you can expect over time—usually expressed as a percentage. Volatility shows how often and how big those wins might be, from steady small hits to rare big jackpots