Here are the terms:
Coin size – the amount bet for each spin.
Coins per spin – How many coins are put in the slot machine each spin.
Hit rate – the rate at which you win on a spin compared with spins when you don't win.
Hold – the money that the slot machine "holds" and doesn't payout. This number can range between 3%and 15%.
Max Bet – the maximum amount of coins you are allowed to bet on any particular machine every time you spin.
Pay Cycle – the time it takes for a machine to payout. There are some people who believe that each machine goes through a cycle where after receiving a certain amount of coins the machine must payout, in order to meet the programmed payout percentage.
Pay Line – the line or lines on a slots machine screen which must have matching symbols lined up for a player to win some coins.
Reels – these are the individual wheels that the symbols are printed on. There are usually three reels on a slots machine but there are some that have two or four. The more reels there are the harder it is to get a winning combination.
Symbols – these are the pictures on the reels. The symbols can be pictures of anything, there are no rules. Typical symbols are particular numbers like "7" for example or pictures of fruit.
Top Prize – the highest number of coins you could possibly win on a particular machine. In order to be eligible to win the top prize you usually need to insert the maximum number of coins per spin – you cannot win this prize if you have not spent enough money.
Winning Combination – a particular sequence of symbols that is needed in order to win a prize.