A Free Spins bonus is an incentive offered by online casinos as an incentive for players to sign up or make a deposit. It is a type of bonus where players are awarded a certain number of free spins to use on a specific set of slot games. Players are usually offered a certain number of free spins, which can range from 10 to hundreds of spins, depending on the casino. Often, these free spin bonuses come with certain wagering requirements.