Many new players mistake a casino bonus for "free cash," but mechanically, bonuses are extra play credits granted under specific conditions. When you claim an offer, the funds are typically placed in a separate Bonus Balance, distinct from your Real Money Balance.
In most cases, the platform will use your real money first. Only after your cash balance is exhausted will the system begin spending your bonus credits. Crucially, while real money can be withdrawn at any time (subject to payment rules), bonus funds must be "converted" into real money by meeting the offer's specific requirements before they become withdrawable.