Bail is a set of pre-trial restrictions that are imposed on a suspect to ensure that they will not hamper the judicial process. It is the conditional release of a defendant with the promise to appear in court when required. In other words "Bail" is either 1. a required amount of money needed to secure release from custody, or 2. a set of rules, terms, or conditions required to secure release from custody.  However in the United States bail usually implies a bail bond, which is a deposit of money or some form of property to the court by the suspect or their family in return for thier release from pre-trial detention. If the suspect does not return to court, the bail is forfeited and the suspect may possibly be brought up on charges of the crime of failure to appear. If the suspect returns to make all their required appearances, bail is returned after the trial is concluded. Often times, people cannot cover the full amount of bail and utilize a bail bond to free their loved ones. So instead of covering the entire bail amount as set by the court system, a bail bondsman  will charge a percentage of the bail amount in what's called a premium. This is compensation for posting someone's bail and taking on the risk and liability that it entails.