A prison is a correctional institution used to detain persons who are in the lawful custody of the government (either because they have been accused of a crime and they await trial or because they have been convicted of a crime and they are serving a sentence).
In the United States, 2.2 million people are incarcerated, and over the course of a year, many millions spend time in prison or jail. Prisons create jobs - over 750,000 men and women work in correctional facilities. Despite correctional methods used in these institutions, 67 percent of former prisoners will be rearrested and 52 percent will be re-incarcerated. The term for this is recidivism, meaning a criminal who has committed a crime, is released, then goes on to commit subsequent crimes.