The Holocaust was unique. There have been many genocides in history. The Nazis murdered many people across different races, religions and ideologies. But their murder of Jews was unique.
(1) Totality The word “genocide” can mean the partial or total destruction of a people. The Holocaust was the attempted total extermination of the Jewish people. All Jews, everywhere, were sentenced to death simply because of their ancestry. The only other race in Europe that was targeted for total extermination were the Romani. But the Germans prioritized the murder of Jews. Romani in Denmark and Greece were not deported for extermination. Jews in those countries, and every country under Nazi occupation, were. Historians estimate that between 25% and 50% of Europe’s Romani were killed during WW2. For the Jews, it was close to two-thirds. The Slavs were brutalized and intended to be enslaved or deported, but the Nazis did not attempt to exterminate them completely. https://encyclopedia.ushmm.org/content/en/article/remaining-jewish-population-of-europe-in-1945
(2) Racial hatred. The Jews were targeted because of who they were. It didn’t matter what a Jewish person did. They were sentenced to death simply because of their ancestry. The only other people subject to similar, but not identical, ethnic hatred were the Romani. Slavs were to be starved, enslaved or deported. Slavs were murdered in reprisal for partisan uprisings, but this isn’t the same thing as murdering someone for their race. The Nazis murdered communists, Christians and other dissidents based on their actions, not their race.
(3) Industrial organization. The Nazi economy was organized around prioritizing the Holocaust. Jewish deportees to death camps were given priority for trains over the Wehrmact. The death camps were set up and organized in a deliberate, industrial fashion.
(4) It was its own end. The Holocaust was not a means to an end. It was the entire purpose of the Nazi regime. Civilians murdered in reprisal for partisan uprisings were intended to stop the partisan uprisings. Communist and Christian dissidents were murdered to stop dissent against the Nazi regime. Jews were murdered simply because the Nazis hated them.
(5) The perpetrators were common citizens. An astute observation from Emil Fackenheim: The people who carried out the “Final Solution” were primarily average citizens. Fackenheim calls them “ordinary job holders with an extraordinary job.” They were not perverts or sadists. “The tone-setters,” he says, “were ordinary idealists, except that their ideals were torture and murder.” https://www.jewishvirtuallibrary.org/what-makes-the-holocaust-unique
I have noticed that in most forms of media today, the uniqueness of Nazi Germany’s attempted extermination of the Jews is hardly ever mentioned. Other victims of Nazi Germany are lumped in with Jews without acknowledging the uniqueness of what Germany did to the Jews. Unfortunately, this attitude seems to be becoming more common, so we need to do our best to spread awareness so that people truly understand what Nazi Germany did to the Jews.