Very different and it is best to find out about them in advance. There are casinos that treat winnings from free spins like a normal bonus. You have to wager it 30 or even 40 times before you can pay it out. It is not necessary to mention that this is not very lucrative. Other casinos, however, have no wagering requirements and you can pay out the winnings immediately - if they are above the limit of the minimum payout.