You should do as much research possible and browse up if you don't fully appreciate the concept of fixed odds gaming.
Say the payout percentage for slots is 96.5%, that means that for the particular game, a total of 96.5% of all bets in order to re-won, keeps 3.5% from a cycle. https://hocvienboardgame.net/tin-tuc/choi-lo-de-tai-rikvip-trai-nghiem-thu-vi/