5 Reel Slots
Then you have the five 5 Reel Slots. This multiplies the number of combinations you can get obviously versus a 3 reel slot (which doesn´t necessarily mean that the payout is greater by the way).
Other things that vary from games to game will be number of paylines, bonus features, wild, scatter and multiplier symbols.
Often one brand of slots can have a 3 reel and a 5 reel version.
An example of a 5 reel slot is Mega Moolah (famous for its huge progressive jackpots). Mega Moolah is a 5 reel, 25 payline, and 125 coin slot.
This 5 reel slot has a top jackpot minimum of one million, and then 3 other jaclpot tiers: 10 000, 100 and 10. You can play with a minimum stake of just 0.01 per line, or go for the max and play 5 coins per line at 0.05 for 25 Lines.