It’s a loan. You pay a percentage of the bond (typically 10% or 15%) and the bondsman puts up the bond for you.
Basically it is a loan where you pay all of the interest at the beginning, and the bondsman gets the principal back from the court once you complete your appearance obligations.
They post the bail. A certain percentage of that bail is to be cash, and the rest is collateral, such as a car title. Or it can be all cash. No, it’s not a loan. Once the defendant appears for court, the car title would go back to it’s owner. Or the rest of the money(minus that certain percentage that the bailbondsman charges) goes back to whoever was dumb enough to bail the person out. If the defendant doesn’t show up for court, the bailbondsman has him a vehicle he can sell for money, or gets to keep the extra cash.
Edit: At least that’s how it works in my state. It might be different in each state. Just google bailbondsmen, laws regarding that, and so on.
Not a loan. You pay the 10% that is normally required and they post a guarantee that you will show up in court. If you don’t, they will come after you for the full amount of the bail/bond. You also pay a fee for this service.