High volatility means that the payout frequency will be low, but the payout amount will be high. Low volatility, on the other hand, indicates that payouts will be made frequently, but the payout amount will be low. Which of these is better is a personal choice. If you have a limited budget, low volatility slots may be a better choice because you start winning earlier. If you don't have a budget problem, high volatility slots may be more satisfying.