Prisons are for long term detention. There are also many different prison types that serve different purposes. Prisoners are placed in a specific type of prison based on the security risk they pose. Your inmate's profile determines where the BOP designates his custody level. Normally, inmates are segregated in a way that assigns them based on the nature of their crimes, and for safety reasons. High security institutions, also known as United States Penitentiaries (USP), have highly secured perimeters featuring high walls or reinforced fences, guard towers, multiple- and single-occupant cell housing, the highest staff-to-inmate ratio, and close control of inmate movement. USP does not always mean high security. Leavenworth in Kansas was high security; it is now medium security but still called a USP. Nearly all high security institutions also have adjacent minimum-security camps to provide the off complex work that supports the high security institution. Inmate moement is heavily restricted and monitored. A Federal Correctional Institution (FCI) pertains to medium or low security prisons or other detention centers. These facilities are classified according to the type of prisoners being housed. For non-serial prisoners, they can be detained in a minimum correctional facility. For the graver type of prisoners, they can be placed in a medium correctional while the high or maximum security facility is only for those prisoners who are very lethal and serial. Prisons can have a long range of amenities like exercise areas, classrooms and even a place for worship. Two or more inmates can share the same prison cell which is why prison guards must monitor all detainees closely to know if trouble is already on the rise or not. The inmates can do lots of things including the participation in vocational and educational programs.