Slot machines work through a process of random number generation (RNG) and programmed payout percentages.

• Random number generation (RNG): RNG is used to determine the outcome of each spin. The RNG is constantly generating random numbers, even when the machine is not in use. When a player hits the spin button, the RNG selects a random number that corresponds to a specific symbol combination on the reels.
• Reels and symbols: The reels on a slot machine are the rotating vertical columns that contain the symbols. The number of reels can vary depending on the machine, but most have three or five. The symbols on the reels can be anything from fruits and numbers to characters and other images.
• Payout table: Each slot machine has a payout table that displays the different symbol combinations and their corresponding payouts. The payout table also shows the payout percentage for the machine, which is the amount of money the machine pays out over time compared to the amount of money players put in.
• Betting: Before spinning the reels, players must place a bet. They can usually choose how much they want to bet per spin and how many paylines they want to activate. Paylines are the horizontal lines on which matching symbols must land for a payout.
• Spinning the reels: Now for the best bit! Once the player has placed their bet, they can hit the spin button to start the game. The reels will spin, and when they come to a stop, the RNG will determine the outcome of the spin. If the symbols on the reels match a winning combination on the payline(s), the player will receive a payout according to the payout table.
• Bonus features: Many slot machines also have bonus features, such as free spins, multipliers, and bonus games, which can increase the player's chances of winning.

A progressive jackpot is a type of jackpot in a slot machine where the value of the jackpot increases over time as more players place bets on the game. A small percentage of each bet placed by each player is added to the jackpot, creating a growing pool of money that can be won by a lucky player.

Progressive jackpots can be linked to a single machine or linked across multiple machines on the gaming floor, this allows the jackpot to grow very quickly.

In order to win a progressive jackpot, players usually need to land a specific symbol combination or trigger a specific bonus feature on the game.

Once a progressive jackpot is won, the jackpot resets to a predetermined amount and begins to grow again as more players place bets on the game.