Deposit bonus codes are promotional offers provided by online casinos and betting sites to attract new players and retain existing ones. By entering a specific code during the deposit process, users can unlock bonuses such as extra cash, free spins, or enhanced odds. These incentives enhance the gaming experience, allowing players to explore more games or increase their betting potential. However, it's essential to read the terms and conditions associated with these codes, as they often come with wagering requirements and expiration dates.