When certain symbols appear in a winning combination a special feature of the particular game theme is activated, which is a Bonus. The player is presented with several items on a screen from which to choose. After choosing items a number of credits is revealed and awarded. A mechanical device, such as a spinning wheel is used by some bonuses. It is used in conjunction with the bonus for displaying the amount won.
Candle is a light on top of the slot machine. It flashes when change is needed and hand pay is requested.
A grouping of slot machines, usually in a circle or oval formation are called Carousel.
There is a container where the coins that are immediately available for payouts are held called Coin hopper. The hopper is a mechanical device that rotates coins into the coin tray when a player collects credits. There is a coin diverter used for redirecting excess coins into a drop bucket, or drop box when a certain preset coin capacity is reached.
Credit meter is a visual display of the amount of money or credits on the machine.
Drop bucket or Drop box is a container located in a slot machine's base where excess coins are diverted from the hopper. It is generally used in low denomination slot machines. A drop box can be found in high denomination slot machines. A drop box contains a hinged lid with one or more locks whereas a drop bucket doesn't contain a lid. There is a scheduled basis on which the contents of drop buckets and drop boxes are collected and counted.
EMG is Electronic Gaming Machine.
The term Hand pay means 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. At the level where the operator must begin to deduct taxes the maximum amount is set. A short pay can also result in a and pay.
Hopper fill slip is a document 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 indicates 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. You will have to stand while playing Stand Up or Upright slot machines.
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.
The process of dramatizing a win by playing sounds while the meters count up to the amount that has been won is Rollup.
The term Short pay is used to mean a partial payout made by a slot machine, which is less than the amount due to the player is called Short pay. It can happen 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.
The manufacturer for all slot machines provide them with a document 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.

Know what you are playing.
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.
Slots shouldn't be a stress for you, just enjoy. Be smart and change oyur bets according to your luck.