From 1941 to 1945, Jews were systematically murdered in one of the deadliest genocides in history, which was part of a broader aggregate of acts of oppression and killings of various ethnic and political groups in Europe by the Nazi regime. Under the coordination of the SS, following directions from the highest leadership of the Nazi Party, every arm of Germany's bureaucracy was involved in the logistics and the carrying out of the genocide. Other victims of Nazi crimes included ethnic Poles, Soviet citizens and Soviet POWs, other Slavs, Romanis, communists, homosexuals, Freemasons, Jehovah's Witnesses and the mentally and physically disabled. A network of about 42,500 facilities in Germany and German-occupied territories was used to concentrate victims for slave labor, mass murder, and other human rights abuses. Over 200,000 people are estimated to have been Holocaust perpetrators.
How it started?
On 7 November 1938, Jewish minor Herschel Grünspan assassinated Nazi German diplomat Ernst vom Rath in Paris. The Nazis used this incident a pretext to go beyond legal repression to large-scale physical violence against Jewish Germans. What the Nazis claimed to be spontaneous "public outrage" was a wave of pogroms instigated by the Nazi Party and carried out by SA members and affiliates throughout Nazi Germany, at the time consisting of Germany proper, Austria, and Sudetenland. These pogroms became known as Kristallnacht ("Crystal Night" or "Night of Broken Glass"). Jews were attacked and Jewish property was vandalized. Over 7,000 Jewish shops and more than 1,200 synagogues (roughly two-thirds of the synagogues in areas under German control) were damaged or destroyed.
Concentration Camps
The Third Reich first used concentration camps as places of incarceration. And though death rates were high—with a mortality rate of 50%—they were not designed to be killing centers. After 1939, the camps increasingly became places where Jews and POWs were either killed or made to work as slave laborers, undernourished and tortured. By 1942, six large camps were built in Poland solely for mass killing. It is estimated Germans established 15,000 camps and subcamps in the occupied countries, mostly in eastern Europe. New camps were founded in areas with large Jewish, Polish intelligentsia, communist, or Roma and Sinti populations, including inside Germany. Prisoner transportation was often carried out under horrifying conditions in rail freight cars; many died before reaching their destination.
Ghettos
After invading Poland, the Nazis established ghettos in the incorporated territories and General Government to confine Jews. The ghettos were formed and closed off from the outside world at different times and for different reasons. Ghettos were intended to be temporary until the Jews were deported. But deportation never occurred. Instead, the ghettos' inhabitants were sent to extermination camps.
Burning Synagogue on Kristallnacht
Auschwitz I and Auschwitz II Birkenau - the biggest concentration camps
Ghetto in Warsaw
Source : wikipedia.com