A super-maximum security (supermax) or administrative maximum (ADX) prison is a "control-unit" prison, or a unit within prisons, which represents the most secure levels of custody in the prison systems of certain countries.

The objective is to provide long-term, segregated housing for inmates classified as the highest security risks in the prison system and those who pose an extremely serious threat to both national and global security.

A prison officer or corrections officer is a uniformed criminal justice official responsible for the custody, supervision, safety, and regulation of prisoners. They are responsible for the care, custody, and control of individuals who have been convicted of a crime and sentenced to imprisonment. They are also responsible for the security of the facility and its property as well as other law enforcement functions. Most prison officers or corrections officers are employed by the government of the jurisdiction in which they operate, although some are employed by private companies that provide prison services to the government.