When you pick an online slot, knowing the RTP tells you how much it pays back...

https://www.nav-bookmarks.win/when-you-play-online-slots-understanding-rtp-and-volatility-is-key-to-knowing

When you pick an online slot, knowing the RTP tells you how much it pays back over time—think of it as a rough payout roadmap. Volatility sets the pace: low means frequent small wins, high swings for bigger payouts