A person's first thought upon landing in jail is often how to get out -- and fast. The usual way to do this is to "post bail". Bail is cash or a cash equivalent that an arrested person gives to a court to ensure that he will appear in court when ordered to do so. If the defendant appears in court at the proper time, the court refunds the bail. But if the defendant doesn't show up, the court keeps the bail and issues a warrant for the defendant's arrest.