All the player has to do is drop coins in the slot and heave the handle or push the spin button.
The payoff table tells players what the winning groupings of symbols are for that machine and what each combination pays based on the number of coins put in for the spin. Players have a much superior chance of hitting any of the lower-paying combinations.
There are essentially two kinds of slot machines: flat tops / straight slots, and progressives. These slots are fundamentally the same, but for one feature: flat tops will pay the winner a prearranged amount, whereas progressive slots have a jackpot that raises by a percentage of each coin played. Sometimes a number of progressive machines feed into one jackpot where any machine in the group can win, and the jackpot grows into an exorbitant amount. These groupings can be a number of machines in one casino, or can be tied to all of the same machines in a whole state. Progressive machines can be recognized by flashing electronic payoff signs displayed either on top of the machine or above a grouping.