What were the Einsatzgruppen and what was their role in the murder of the Jews?

Einsatzgruppen means "task forces." The SS set up such units before they entered Austria, Czechoslovakia, Poland, and the Soviet Union. The task of the Einsatzgruppen in Poland was to terrorize the local population and murder anyone whom the SS deemed undesirable. The most infamous Einsatzgruppen of all were formed before the invasion of the Soviet Union in June 1941. Their primary task was to destroy what they regarded as the ideological infrastructure of the Soviet Union: political commissars, members of the Communist party, and above all, Jews.

Einsatzgruppen advanced into the Soviet Union along with the German army. Wherever they stopped, they collected and shot in cold blood as many Jews as they could find (first Jewish males, and soon thereafter Jewish women and children, as well). They wrote detailed daily reports on their activities, copies of which still exist. According to their own incomplete reports, they killed at least 900,000 Jews and were assisted by other units in the murder of hundreds of thousands more.