Three reel - The most common kind of slot machine is the three reel, which means there are three reels that spin and stop individually, with winning combinations of symbols paying out.

Five reel- The five-reel machine is basically the same as the three reel, it just has two additional lines to match symbols on. Some machines will payout for combinations that have less than five matches. But, there are some five-reel slot machines that only have one payline.

Payline - The payline is the line on the machine that symbols have to match up on to hit the jackpot. The number of paylines varies from machine to machine. You don't always have to play all available paylines. For example, on a five-line machine, you can put in two coins to only play two lines.

Most slot machines will have three reels and one payline. Sometimes, you can bet more than one coin at a time on these machines, but all wagers will be on the same payline. Some three-reel machines will have three paylines.

There is usually anywhere from five to 15 paylines on a five-reel machine. Some of these combinations can even include diagonal lines. You should always check what the paylines are before playing because they can vary from slot machine to slot machine.

Progressive jackpot - This is when the jackpot is constantly getting bigger. Most machines have the jackpot raised at a set amount, such as going up by a dime on each spin. There are not many slot machines that work this way - most will have a fixed jackpot.