Modern casino slots are controlled by computer chips and software, as well as the win percentages are preprogrammed in to the software.

Casino slots have Random Number Generators (RNG) that are continually generating combinations, even when the equipment is just not being played.

Running concurrently with the RNG of the casino slot machine will be the payout percentage.

The payout percentage controls how much the slot machine will payout, for example the payout percentage may be 90%, excellent online gambler (he said) meaning the slot game will payout 90% of all the bets played and the casino only gets to keep 10%.

This isn't to state that every time you bet 10 credits you will receive 9 in return - where will be the fun and excitement in that? Instead the casino slot machine game will not pay out for a while, and then suddenly go on a hot streak and also you might hit a big jackpot.

So in essence the slot machine takes all the money played into it and pays it out to few lucky winners. The casino only gets to keep a relatively small percentage of all the bets placed.

The casino slot software controls every included in the machine, from the flashing lights to the spinning of the reels.

When you hit spin on the slot machine, a combination is produced by the RNG which corresponds to the pictures on the reel.