How much knowledge did the Allies have about the death camps prior to their arrival and liberation? Did the units who found them know what they were getting into when they went through the gates?
Have tackled this question here https://www.reddit.com/r/AskHistorians/comments/dde0ka/comment/f2jsksm?context=3
Also see this thread by u/estherke and yours truly: https://www.reddit.com/r/AskHistorians/comments/dgkquc/comment/f3fn22f
Note that very few extermination camps were actually liberated (Auschwitz and Majdanek by the Soviets) as most of them were simply destroyed by the Nazis themselves, leaving not much beyond fields strewn with ashes (this happened to Treblinka, Belzec, Sobibor, Kulmhof, Maly Trostenets...). However the term "death camp" was often applied in the early press to concentration camps like Dachau, Belsen, Buchenwald...