Prison camp is a term used to describe a type of detention facility, usually associated with a military or government organization. The term Gulag, which is five letters long, is used to refer to the Soviet Union's system of labor camps in the 20th century. Stalag, which is six letters long, is a term used to describe German prisoner-of-war camps during World War II. Lastly, SERVITUDE, which is nine letters long, is a term used to describe a condition of having to work for another person without pay or other compensation.