A special feature of the particular game theme activated when certain symbols appear in a winning combination is Bonus. The player can choose from several items shown on a screen. As the player chooses items, a number of credits is revealed and awarded. A mechanical device, such as a spinning wheel is used by some bonuses. To display the amount won it works in conjunction with the bonus.
Candle is a light on top of the slot machine. When change is needed, hand pay is requested or a potential problem with the machine appears it flashes.
The term carousel is used to denote a grouping of slot machines, usually in a circle or oval formation.
There is a container where the coins that are immediately available for payouts are held called Coin hopper. When a player collects credits this mechanical device rotates coins into the coin tray. A coin diverter automatically redirects excess coins into a drop bucket, or drop box when a certain preset coin capacity is reached.
Credit meter is used for displaying the amount of money or credits on the machine.
Drop bucket or Drop box is used for diverting exess coins from the hopper. A drop bucket can usually be found in low denomination slot machines. As for high denomination slot machines they use a drop box. A drop box contains a hinged lid with one or more locks whereas a drop bucket doesn't contain a lid. The casino collects and counts the contents of drop buckets and drop boxes.
Electronic Gaming Machine is called EGM.
Hand pay refers to a payout made by a slot attendant or cage, rather than the slot machine. When the amount of the payout exceeds the maximum amount that was preset by the slot machine's operator a hand pay occurs. Usually, the maximum amount is set at the level where the operator must begin to deduct taxes. A hand pay can also be a result of a short pay.
There is Hopper fill used to record the replenishments of the coin in the coin hopper after it becomes depleted as a result of making payouts to players. The slip exists to indicate the amount of coins placed into the hoppers, the signatures of the employees involved in the transaction, the slot machine number and the location and the date.
Low Level or Slant Top slot machines include a stool so you can sit and play. Stand Up or Upright slot machines are played while standing.
The term Optimal play means a payback percentage based on a gambler using the optimal strategy in a skill-based slot machine game.
A straight or zigzagged line that crosses through one symbol on each reel, along which a winning combination is evaluated is called Payline. Classic spinning reel machines usually have up to nine pay lines, while video slot machines may have as many as one hundred.
Rollup is the process of dramatizing a win by playing sounds while the meters count up to the amount that has been won.
Short pay refers to a partial payout made by a slot machine, which is less than the amount due to the player. This occurs if the coin hopper has been depleted as a result of making earlier payouts to players. In this case the remaining amount will be paid as a hand pay or an attendant will come and re-fill the machine.
A document provided by the manufacturer for all slot machines is called Theoretical Hold Worksheet. It indicates the theoretical percentage that the slot machine should hold based on adequate levels of coin-in. The worksheet also indicates the reel strip settings, number of coins that may be played, the payout schedule, the number of reels and other information.
Weight count is an American term, referring to the dollar amount of coins or tokens removed from a slot machine's drop bucket or drop box and counted by the casino's hard count team through the use of a weigh scale.

To know what you are playing is necessary for you.
Always make sure that you insert the correct amount of coins into a machine. Your credits should be cashed out before you leave the machine.
Only if you have fun your gambling won't be stressful. If you feel lucky increase your bets and vice-versa.