When you pick an online slot, knowing its RTP and volatility can save you from...

https://wool-wiki.win/index.php/Low_Volatility_Slots_for_Casual_Players:_What_You_Really_Need_to_Know

When you pick an online slot, knowing its RTP and volatility can save you from surprises. RTP tells you the average return over time, usually around 95-97%, while volatility shows how wild or calm the wins might be