A military prison is a prison operated by the military. Military prisons are used variously to house prisoners of war, unlawful combatants, those whose freedom is deemed a national security risk by the military or national authorities, and members of the military found guilty of a serious crime. Thus, military prisons are of two types: penal, for punishing and attempting to reform criminals within the military, and confinement-oriented, where captured enemy combatants are confined for military reasons until hostilities cease.
Most militaries have some sort of military police unit operating at the divisional level or below to perform many of the same functions as civilian police, from traffic-control to the arrest of violent offenders and the supervision of detainees and prisoners-of-war.
The Australian Defence Force currently has a single prison, the Defence Force Correctional Establishment at Holsworthy Barracks in Sydney. This prison houses military personnel sentenced to between 14 days to two years imprisonment. In addition, there are 15 detention centres located within military bases across Australia.
The Canadian Forces have one military prison, the Canadian Forces Service Prison and Detention Barracks (CFSPDB) (colloquially known as Club Ed), located at Canadian Forces Base Edmonton. Canadian Forces personnel who are convicted by military courts and receive a sentence of 14 days or more are incarcerated at CFSPDB. Men, although in the same prison, are kept separate from women. The prison is maintained and controlled by the Canadian Forces Military Police, although NCOs from various branches of the Canadian Forces serve at the prison as staff. Service personnel who are convicted of less serious offences are considered to be in "detention", and undergo a strict military routine aimed at rehabilitation for their return to regular military service, whereas personnel convicted of more serious offences are considered to be in "prison" and upon completion of their sentence they are released from the military. Serious offenders with sentences longer than 2 years are transferred to the Canadian federal prison system after serving 729 days, to complete their sentence in the civilian prison system, followed by release from the Canadian Forces. Any service personnel serving a sentence of 14 days or less are held in local base Military Police Detachment cells at the various Canadian Forces Bases within Canada.