The slots payout refers to the percentage of money that a particular slot gives back to players after a considerable amount of spins. Usually, the rate ranges from 75% to up to 97%. In terms of winnings, gamblers can expect better results after a large number of spins. Also, it's a value that can be used to compare different slots and choose the ones that, in the long run, seem to give more return to players.
Online slots are tested by independent organizations to determine if their claimed payout percentage is actually fair and correct. The terms "hot" and "cold" are referred respectively to slots with higher and lower payouts.