My school never told me what the Holocaust was, can someone explain?

The word “Holocaust,” from the Greek words “holos” (whole) and “kaustos” (burned), was historically used to describe a sacrificial offering burned on an altar. Since 1945, the word has taken on a new and horrible meaning: the ideological and systematic state-sponsored persecution and mass murder of millions of European Jews (as well as millions of others, including Romani people, the intellectually disabled, dissidents and homosexuals) by the German Nazi regime between 1933 and 1945. To the anti-Semitic Nazi leader Adolf Hitler, Jews were an inferior race, an alien threat to German racial purity and community. After years of Nazi rule in Germany, during which Jews were consistently persecuted, Hitler’s “final solution”–now known as the Holocaust–came to fruition under the cover of World War II, with mass killing centers constructed in the concentration camps of occupied Poland. Approximately six million Jews and some 5 million others, targeted for racial, political, ideological and behavioral reasons, died in the Holocaust. More than one million of those who perished were children.