The most critical concept to understand is that a casino bonus is not "free cash" upon arrival; rather, it consists of extra play credits designed to extend your gaming experience. When you claim an offer, these credits are typically stored in a separate Bonus Balance, distinct from your Cash Balance.
These two balances behave differently. Generally, your real money (Cash Balance) is used first for betting. While you can withdraw your cash balance at any time (subject to general withdrawal rules), bonus funds are locked until specific conditions are met. Once the conditions are satisfied, the bonus funds "convert" into real cash. Understanding this separation helps you manage your bankroll and avoid confusion when viewing your account total.