Coins Size - This is the amount of each bet, on most machines you can play more than one coin. Common coin sizes range from one cent to five dollars.  Playing a one dollar coin size machine at three coins per spin would cost you  three dollars each spin.

Hit Frequency - This is the frequency at which winning spins occur. This term is often used with bonus feature slots as the amount of spins between the bonus feature being won. A higher hit frequency is better than a low one although you have to take the machines pay cycle into account which can make measuring this difficult.

Hopper - In land based slot machines this is where the coins you put in are  stored. The hopper can be empty so you should always be sure that you have  been paid out the correct amount before playing on. If the amount of coins is less than you should have won, call an attendant who will pay you the additional  winnings.

Max Bet - This is the maximum amount of coins that you can play per spin. It is of the most importance when playing progressive slots because usually the max bet must be played to qualify for the jackpot.

Multi-line - This simply means a slot machine with more than one pay line. Slot machines can have up to 20 different pay lines and it pays to read the machine before you play to avoid any disappointment.

Progressive Jackpot - This is a top prize which grows as people play. Often these machines are linked up at several casinos so the jackpots can grow very large. As always "reading" the machine before you play is a must.

Pay line - This is the line on which you must line up the symbols to score a win. Modern slots can have from 1 to 20 pay lines.

Pay Table - The pay table is the section of the slot machine which tells you haw  much you will win for each type of combination. The pay table will also tell you if  there are bonus features and if max bet will reward you with a bonus top prize.

Reels - The rotating part of the slot machine, the symbols are on the reels. Modern slot machines can have from 3 to 5 reels.

Symbols - These are the pictures which you must line up to score a win. Common examples are "BAR" symbols and "7" symbols.

Wild Multiplier - These are wild symbols (See Below) that when hit also multiply your win. For instance the highly popular Double Diamonds has a two times wild multiplier.

Wild Symbol - This acts like a joker and will count for any other symbol, often  making up that crucial third symbol in a winning combination. Some slots have  wild symbols which also multiply the win for each wild that is present in a combo, these slots are of course very popular.