Military prison
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.
Military jail
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.
Canada