Thus although the Nazi 'Final Solution' was one genocide among many, it had features that made it stand out from all the rest as well. Unlike all the others it was bounded neither by space nor by time. It was launched not against a local or regional obstacle, but at a world-enemy seen as operating on a global scale. It was bound to an even larger plan of racial reordering and reconstruction involving further genocidal killing on an almost unimaginable scale, aimed, however, at clearing the way in a particular region – Eastern Europe – for a further struggle against the Jews and those the Nazis regarded as their puppets. It was set in motion by ideologues who saw world history in racial terms. It was, in part, carried out by industrial methods. These things all make it unique.
Peter Hayes (How Was It Possible? A Holocaust Reader, 2015): "The Holocaust, the Nazi attempt to eradicate the Jews of Europe, has come to be regarded as the emblematic event of Twentieth Century ... Hitler's ideology depicted the Jews as uniquely dangerous to Germany and therefore uniquely destined to disappear completely from the Reich and all territories subordinate to it. The threat posted by supposedly corrupting but generally powerless Sinti and Roma was far less, and therefore addressed inconsistently in the Nazi realm. Gay men were defined as a problem only if they were German or having sex with Germans or having sex with Germans and considered 'curable' in most cases. ... Germany's murderous intent toward the handicapped inhabitants of European mental institutions ... was more comprehensive ... but here, too, implementation was uneven and life-saving exceptions permitted, especially in Western Europe. Not only were some Slavs—Slovaks, Croats, Bulgarians, some Ukrainians—allotted a favored place in Hitler's New Order, but the fate of most of the other Slavs the Nazis derided as sub-humans ... consisted of enslavement and gradual attrition, not the prompt massacre meted out to the Jews after 1941."
“ ...Here over an acre of ground lay dead and dying people. You could not see which was which... The living lay with their heads against the corpses and around them moved the awful, ghostly procession of emaciated, aimless people, with nothing to do and with no hope of life, unable to move out of your way, unable to look at the terrible sights around them ... Babies had been born here, tiny wizened things that could not live ... A mother, driven mad, screamed at a British sentry to give her milk for her child, and thrust the tiny mite into his arms, then ran off, crying terribly. He opened the bundle and found the baby had been dead for days.
Bergen-Belsen [ˈbɛʁɡn̩.bɛlsn̩], or Belsen, was a Nazi concentration camp in what is today Lower Saxony in northern Germany, southwest of the town of Bergen near Celle. Originally established as a prisoner of war camp, in 1943, parts of it became a concentration camp. Initially this was an "exchange camp", where Jewish hostages were held with the intention of exchanging them for German prisoners of war held overseas. The camp was later expanded to accommodate Jews from other concentration camps.