Online slots evolved from simple three-reel classics to diverse games with...

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

Online slots evolved from simple three-reel classics to diverse games with video themes, bonus rounds, and dynamic Megaways mechanics that change paylines each spin. They now include jackpots and Slingo hybrids mixing slots with bingo elements