The volatility of a slot machine refers to how frequently you win and lose money at the game, based on your average number of bets over time. While each spin of the reels in a slot machine has its own chance of winning or losing, over the long term you’ll either win more than you lose or vice versa. A low volatility slot machine will win less often than it loses, while a high volatility slot machine will do the opposite; lose more often than it wins over the long term.