Online slots evolved from simple three-reel games into diverse options...

https://thefiguremagazine.com/classic-reels-to-megaways-how-online-slots-became-more-varied/

Online slots evolved from simple three-reel games into diverse options featuring video themes, interactive bonus rounds, and unique mechanics like Megaways and Slingo. Players can enjoy various styles, from classic reels to progressive jackpots