Imprisonment (from imprison, via French emprisonner, originally from [Latin] prensio, arrest, from prehendere, prendere, "to seize") in law is the specific state of being physically incarcerated or confined in an institutional setting such as a prison.[1] Courts of the United States, including the U.S. Supreme Court, have recognized that the minimum period in an indeterminate sentence that was actually imposed by a court of law is the official term of imprisonment.[2][3] In other words, any "street time" (e.g., probation, parole, or supervised release) that was ordered by the court as part of the defendant's punishment does not constitute term of imprisonment.[4]

Imprisonment in other contexts is the restraint of a person's liberty, for any cause whatsoever, whether by authority of the government, or by a person acting without such authority. The latter case constitutes "false imprisonment". Imprisonment does not necessarily imply a place of confinement but may be exercised by any use or display of force, lawfully or unlawfully. People become prisoners, wherever they may be, by the mere word or touch of a duly authorized officer directed to that end.[5]

Sometimes gender imbalances occur in imprisonment rates, with incarceration of males proportionately more likely than incarceration of females. Ethnic minorities can also contribute disproportionate numbers to prison populations.[6]