The object of the game is to win money from the machine. The game usually involves matching symbols, either on mechanical reels that spin and stop to reveal one or several symbols, or on a video screen. The symbols are usually brightly colored and easily recognizable, such as images of fruits, and simple shapes such as bells, diamonds, or hearts.
Most games have a variety of winning combinations of symbols, often posted on the face of the machine. If a player matches a combination according to the rules of the game, the slot machine pays the player cash or some other sort of value, such as extra games.

The suspense of waiting for the reels to stop spinning, the thrill of hearing the coins clanging together as they drop into your tray, if these emotions.
There is no doubt that in the gambling world, the slot machine pulls in more profits than any other game, in fact, the combined gross payout of the slot machine is almost as much as the total of every other casino games payout collectively. 
Once the player deposits an amount of coins into the slot and pulls the lever at the side of the machine (or hits the spin button) an axis inside the machine is activated which causes the reels to rotate freely and eventually come to a stop. Once stopped, if the symbols that are printed on these reels line up on one of the pay lines, in a combination that is set out on the pay schedule, than you will win the according amount.