How Casino Jackpots Work in Online Games

Lately I’ve been reading about different casino games online because I’m trying to understand how the big prizes actually work. Every time I browse through descriptions or game explanations, the word jackpot shows up again and again. Some games mention huge rewards that players can win, but it’s still not completely clear to me how those prizes appear or why some of them grow over time. I’m not planning to jump into playing right away, I just want to understand the basics first so everything makes more sense when I see these terms. Maybe someone here has already looked into this topic and can explain it in simple words.