A bond is an amount of money paid as a guarantee that, if released, a non-citizen will appear in court for removal hearing. Bonds can be set either by ICE at the time the immigrant is detained or by an Immigration Judge at the time of a bond hearing. Some criteria that Immigration Judges consider include: criminal record, flight risk, and form of relief for which the immigrant intends to file in the future.
Once a bond is set, the family or friends of the immigrant can either pay the full amount to have the person released or hire a bond company and offer some form of collateral to the bond company. Each such immigration bond company has different requirements.
If you are released from detention on bond, you must still make all scheduled court appearances and may still ultimately be removed from the United States. If you do not show up to court when you are scheduled to appear, the bond money will not be returned and you will be ordered deported in absentia (absent)
Once an immigrant who was released on bond has completed all of his court hearings (or has chosen to voluntarily leave the country), his bond money will be returned to the individual who signed the bond (guarantor) papers.