If your bail is set at $2500, you have two options: you can pay it in full now and receive a refund once you appear in court, or you can pay a bail bondsman 10% of the total to put the money up for you. In this case, you would pay the bondsman $250.
The money you spend on a bondsman is not refundable. After you attend your court date, you often get almost the entire sum returned if you paid it yourself.