
A prison, also known as a jail or gaol, penitentiary, detention center, correction center, correctional facility, lock-up or remand center, is a facility in which inmates are confined and denied a variety of freedoms under the authority of the state as punishment for various crimes. Prisons are most commonly used within a criminal justice system: people charged with crimes may be imprisoned until their trial; those pleading or being found guilty of crimes at trial may be sentenced to a specified period of imprisonment. In simplest terms, a prison can also be described as a building in which people are legally held as a punishment for a crime they have committed.

Architecture terrible was an architectural style advocated by French architect Jacques-François Blondel in his nine-volume treatise Cours d'architecture (1771–77). Blondel promoted the style for the exterior design of prisons: the form of the building itself would proclaim its function and serve as a deterrent, and so achieve a "repulsive style" of heaviness that would "declare to the spectators outside the confused lives of those detained inside, along with the force required for those in charge to hold them confined".

In military terminology, a black site is a location at which an unacknowledged black operation or black project is conducted. It can refer to the facilities that are controlled by the CIA and used by the U.S. government in its War on Terror to detain enemy combatants.

The Correctional Labour Camp was a kind of penitentiary institution. Under various names and forms of ownership, they exist practically all over the world, but with the name "Correctional Labour Camp", institutions of this type existed only in the Soviet Union.

In prison terminology a dry cell is a room that prisoners are placed in that lacks any plumbing facilities such as a toilet or shower. In the Federal Bureau of Prisons, a dry cell can be used if a prisoner claims to be unable to urinate for a drug test under direct visual supervision. Prisoners are also sometimes placed in dry cells if they are suspected of having swallowed contraband. The idea is that they will eventually excrete all the contents of their digestive system, and lacking any toilet, they will be unable to dispose of it and thereby prevent prison officials from acquiring the evidence.

Eugene Kontorovich is a legal scholar, specializing in constitutional and international law.
A guard tower is any military tower used for guarding an area. These towers are usually operated by military personnel, and are structures built in areas of established control. These include military bases and cities occupied by military forces. This type of fortification is a variation on the tower incorporated into the walls of castles from history, and are, in the modern day, equipped with such facilities as heavier weapons than those carried by infantry and searchlights.
A halfway house is an institute for people with criminal backgrounds or drug abuse tendencies to learn the necessary skills to re-integrate into society and better support and care for themselves.

An open prison is any jail in which the prisoners are trusted to complete their sentences with minimal supervision and perimeter security and are often not locked up in their prison cells. Prisoners may be permitted to take up employment while serving their sentence.

Owadan-depe is a prison for political inmates in the Ahal Region of Turkmenistan established by the regime of former President Saparmurat Niyazov to incarcerate political opposition supporters, former public officials and prisoners charged with supporting Wahhabism.

The panopticon is a type of institutional building and a system of control designed by the English philosopher and social theorist Jeremy Bentham in the 18th century. The concept of the design is to allow all prisoners of an institution to be observed by a single security guard, without the inmates being able to tell whether they are being watched.

A prison cemetery is a graveyard reserved for the dead bodies of prisoners. Generally, the remains of inmates who are not claimed by family or friends are interred in prison cemeteries and include convicts executed for capital crimes.
A prison farm is a large correctional facility where penal labor convicts are forced to work on a farm, usually for manual labor, largely in open air, such as in agriculture, logging, quarrying, and mining. The concepts of prison farm and labor camp overlap. The historical equivalent on a very large scale was called a penal colony.

Prison slang is an argot used primarily by criminals and detainees in correctional institutions. It is a form of anti-language. Many of the terms deal with criminal behavior, incarcerated life, legal cases, street life, and different types of inmates. Prison slang varies depending on institution, region, and country. Prison slang can be found in other written forms such as diaries, letters, tattoos, ballads, songs, and poems. Prison slang has existed as long as there have been crime and prisons; in Charles Dickens' time it was known as "thieves' cant". Words from prison slang often eventually migrate into common usage, such as "snitch", "ducking", and "narc". Terms can also lose meaning or become obsolete such as "slammer" and "bull-derm."

Prison violence is a daily occurrence due to the diverse inmates with varied criminal backgrounds in penitentiaries. The three different types of attacks are inmate on inmate, inmate on guard, and self-inflicted. These attacks can either be impulsive and spontaneous or well-planned out and premeditated. Factors such as gang rivalries, overcrowding, minor disputes, and prison design contribute to violent attacks. Prisons are trying to avoid, or at least better deal with these situations by being proactive. They are taking steps like placing violent convicts and gang leaders into solitary confinement, balancing the cells by critically examining each inmate to see where they are likely to reside peacefully, reducing blind spots, and training as well as educating the officers.
A prisoner transport vehicle, informally known as a "Sweat Box" amongst British prisoners, is a specially designed or retrofitted vehicle, usually a van or bus, used to transport prisoners from one secure area, such as a prison or courthouse, to another. Less commonly, aircraft, railcars or vessels are also similarly fitted. These vehicles must be highly protected and may feature bars or wire mesh over the windows, bulletproof glass, segregated prisoner compartments, and additional seating for escorting officers.

Red Cross parcel refers to packages containing mostly food, tobacco and personal hygiene items sent by the International Association of the Red Cross to prisoners of war during the First and Second World Wars, as well as at other times. It can also refer to medical parcels and so-called "release parcels" provided during World War II. The Red Cross arranged them in accordance with the provisions of the Geneva Convention of 1929. During World War II these packages augmented the often-meager and deficient diets in the POW camps, contributing greatly to prisoner survival and an increase in morale. Modern Red Cross food parcels provide basic food and sanitary needs for persons affected by natural disasters, wars, political upheavals or similar events.

The separate system is a form of prison management based on the principle of keeping prisoners in solitary confinement. When first introduced in the early 19th century, the objective of such a prison or "penitentiary" was that of penance by the prisoners through silent reflection upon their crimes and behavior, as much as that of prison security. More commonly however, the term "separate system" is used to refer to a specific type of prison architecture built to support such a system.
A stockade is an enclosure of palisades and tall walls, made of logs placed side by side vertically, with the tops sharpened as a defensive wall.