There might be some confusion about Auschwitz.
Auschwitz concentration camp was a *network* of concentration and extermination camps built and operated by the Third Reich in Polish areas annexed by Nazi Germany during World War II.
It consisted of Auschwitz I (the original camp), Auschwitz IIBirkenau (a combination concentration/extermination camp), Auschwitz IIIMonowitz (a labor camp to staff an IG Farben factory), *and 45 satellite camps*.
Here is a map of many of the camps of Europe, to give an idea about the complexity of the Nazis schemes, though many more camps were too small to be shown on this map:
http://i.imgur.com/xuxULrd.jpg
The accepted “civilized” war practice in that era and region was to be fairly humane to POWs. Hitler in his mad vindictiveness (and/or vindictive madness) wanted to PUNISH the Jews, and many other innocent people, that stood in the way of his evil rage. That ended up hampering his war efforts more than helping them. But this was about far more than mere war. It was about a hellish madness.