Usually, you would come across two major bonuses online casino would offer, such as cashable and sticky bonus. The sticky bonus would be free money for your gambling needs given by the casino. It would be taken back by the casino when you withdraw the winnings post meeting the wagering requirements. The cashable bonus would not be the same. Cashable bonus would entail winnings along with the casino bonus given initially. However, it would also need you to meet wagering requirements.
Apart from the aforementioned bonuses, you would come across casino sans depot. It is free money offered by the casino. However, you would be required to open real time account with the casino that offers you with no deposit bonuses. Unlike most casinos that deposit the bonus automatically into your account, some would require to confirm your account through confirmation email before actually depositing the money into your account.