For a while, the slot machine community only cared about RTP, but as resources became more readily available online, the player base found volatility. You already know what volatility is - it's how often a winning combination is produced relative to your average winning amount. There are three types of volatility: low volatility, high volatility, and medium volatility. Low volatility means you will win more, but less. High volatility means you'll need to be patient and play slots while waiting for bigger payouts. The medium volatility tries to balance out and allow you to get the most out of the slot machine. Which one is best for you will depend on some factors unique to your situation. How much can you afford to lose is usually one of them? Are you playing on a tight budget, or do you have more money to spend, allowing you to play a few rounds without making any profit in anticipation of a more substantial victory? It really comes down to slot players choosing their preferred online slot machines, but it's best to take advantage of casino games that suit your personality.