Online casino bonus codes are promotional tools that players can use to unlock special offers, such as free spins, deposit matches, or cashback rewards. These codes are typically entered during the registration process or when making a deposit, providing players with added value and enhancing their gaming experience. Each online casino may have different codes with varying terms and conditions, making it essential for players to read the fine print. Utilizing these bonus codes can significantly boost a player's bankroll, allowing for more extended play and increased chances of winning.