Free spins bonus codes are used in casinos in order to claim free spins on the slots. Depending on the particular promotion this may require you to first deposit some funds.
In order to claim these free spins you will first need to obtain the promotional code. Without this special code you will not be entitled to any free spins. This is in comparison to a signup promotion where free spins are awarded automatically and the use of a code is usually unnecessary. Typically these promotional codes can be found on websites, such as free-spins-casino.com, where they are awarded to specific players upon meeting the requirements.
Once you receive your free spin bonus code you will be required to enter it on the casino site. The casino will recognise your unique code and you will be awarded your free spins!