What was the Holocaust and why is it unique?

The Holocaust was the attempted destruction of European Jews by Nazi Germany from 1933 to 1945. The Holocaust is unique as it is the first time in history when there was a systematic plan by a government to kill all the Jews. During the Holocaust, other groups of people were also targeted, segregated, and killed, including Roma and Sinti (Gypsies), disabled people, those in the LGBTQ+ community, and others.