The real concentration camps were in the soviet union. The gulag was truly a death camp. Auschwitz,Treblinka,Sobibor and others pale by comparison,they look like luxury resorts if you compare them to the typical soviet worker camp. As a matter of fact,while the soviets and the Germans were "allies" for a short while. The nazi regime sent people to actually learn how to make a proper concentration camp,they did not really know what and how to deal with unwanted people. Before the concentration camps, most political prisoners,defectors and people who the regime deemed dangerous,they were held in really good conditions. Something like a white collar prison. Or something similar to the current day quarantine situation. You stayed in a building, you could take walks in the yard at any hour in any day, you had food and decent amenities,no forced labour,no forced nothing,you just could not leave,that is it. You played cards with the guards and did whatever else you could, to pass the time. The soviet gulag was a really simple and effective tool for the state. Let us say you needed to build infrastructure in a remote area of the country, a railroad,a factory a whatever in an area where if you would want to hire people,they would be extremely expensive. You throw millions of your own people, people who might have a different opinion from you in these "reeducation camps", and put them to work. Pretty much all of the major infrastructure work in the soviet union wasn't done by the great patriotic movement,or the great socialists out there,they were done with slave labor from these gulags. Did not matter if you were a writer,a poet,a musician,an artist,an industrialist,you took the shovel and started digging. The alternative was always worse. You would be either beaten to death,tortured for days,weeks even till you died, or simply shot,it depends on how the guards felt that day,what they had for breakfast. But hey, "Uncle Joe" as the western propaganda called Stalin, he needed to look like the good guy, so obviously the German leadership and it's people had to be vilified,demonized. The actual holocaust happened, it's called Holodomor, and it's not the only one,there were other "holodomors" in different countries under the soviet regime.