Before you begin looking at different types of bail bonds, you need to make sure that you are dealing only with a licensed agent. They have certain guidelines and oversight that will protect all parties when you deal with someone holding a bail bondsman license.
The U.S. Congress passed the Bail Reform Act in 1966, allowing defendants to be released with a small financial investment. Basically the bail is an exchange of money, held by the court, until the trial is complete. When you have to make bail for yourself or someone else, you are paying a refundable fee in promise for the return for all proceedings.
When you use a bail agent, they are backed by an insurance company that can pay the monies owed if the defendant does not appear in court. In essence, when you use a bail bondsman, there are fees paid to the bond company and the surety company to cover their service. They are used when the defendant or their agents are unable to cover the full amount of their bail.
Defendants are liable for the entire amount of the bail, and if they decide not to fulfill their obligations to the courts they may be hunted down by bounty hunters hired on behalf of the bail bondsman. Note, there are a few states that have outlawed the practice of earning a profit from posting bail so you cannot hire a bondsman to make bail. In those few states, you would have to find other ways to fund bail.
When someone is arrested, they may or may not need different types of bail bonds. Sometimes they can be realized without charges or released on their own recognizance meaning they do not have to post bail. For others, if bail is an option, the court will set the bail and you can consult a bail bondsman on their process. To see more, read this.