"Concentration camp” is a term that predates its (somewhat euphemistic, when done in retrospect) use for the camps eventually used in the extermnation campaign by the Nazis (which also started out as concentration camps, in the more usual sense, as part of what was nominally a deportation program.)

Though concentration camps are almost always part of systematic, ethnically-targetted abuse, even when they aren't part of genocide campaigns.

The Germans ran work camps, concentration camps, and death camps. Right now the United States is only running two of the three. We have work camps (prisons) and concentration camps (detention facilities).