The word Holocaust (from the Greek for “consumption by fire” or “burnt offering”) refers to the German campaign of mass murder and attempted genocide against European Jews and others between 1933 and 1945. The Holocaust is often divided into five distinct phases:  definition, expropriation, concentration, deportation, and annihilation.

The first phase was the definition and persecution of the Jewish population of Germany by the Nazi Party and the German state between 1933 and 1939.  After Adolf Hitler was appointed Chancellor of Germany in 1933, German state policy became officially antisemitic. Soon, German law defined the Jews as a separate race and took away their citizenship and civil and economic rights.  The Nazis intended to force the entire population of 566,000 German Jews to leave Germany.  More than half of them emigrated during this period.

The second phase, from September 1939 to June 1941, was the concentration of Jewish populations in many German-occupied territories.  During this period, the Nazis confined Jews into holding facilities known as ghettos.  Even though mass-murder was not a part of German anti-Jewish policy during this period, hundreds of thousands of Jews in camps and ghettos died of starvation, disease, abuse, and exhaustion from their living conditions and forced labor.  

The third phase of the Holocaust was the systematic effort to murder every Jewish man, woman, and child in German-occupied Europe.  After invading the Soviet Union in 1941, the Germans built an efficient killing operation.  SS soldiers in mobile death squads called Einsatzgruppen shot Jews in conquered Soviet territory by the hundreds of thousands.  After the Final Solution became German policy in 1941, millions of Jews were deported from all over Europe to death camps which were equipped with gas chambers and crematoria.  Before the Allied powers defeated Germany in May 1945, the Holocaust had claimed the lives of some six million Jewish human beings — two-thirds of the Jewish population of Europe.  

While the principal victims of the Holocaust were Jews, the Nazis also targeted other groups in Europe for persecution or extermination.  The Nazis murdered 100,000 to 200,000 Gypsies, more than 100,000 disabled Germans (who were considered an embarrassment to the German “Master Race”), and thousands of communists, political prisoners, German male homosexuals, and Jehovah's Witnesses.  Also, after the German invasion of the Soviet Union in 1941, millions of Soviet prisoners of war (who were regarded as both political enemies and “sub-humans”) were allowed to starve to death or were brutally exploited for slave labor.