A cash bail bond is the most simple bail bond because the entirety of the bond is paid with cash. After someone is arrested and a bail bond is set, that person has the option to pay the bond in full. If you have the full amount available in cash, the Sheriffs Department will take your cash and release you based on the payment of the cash bond.
Another instance where a cash bond may be required is when a judge sets a cash bond requirement. This means, that the judge requires the full amount to be paid in order to have the person release. This happens pretty frequently in child support cases. In order to get the parent to pay, a judge may remand them into custody and set a cash bond. Once the bond is paid in full then the person is released from custody. When a cash bond requirement is set, then it becomes the duty of the person to raise the actual amount of the bond in cash in order to be released.