In 1933, Germany signed the Haavara Transfer Agreement... and by 1939, they sent out their troops to put that agreement into practice...
in the round up (Lapanka)... prisoners were taken to either work camps (Arbeitslager) or concentration camps (Konzentrationslager)...
there was at least 1,200 of these work camps, some where Jewish prisoners would be taken, and some where other prisoners would be taken...
somewhere between 12 - 15 million people were abducted and taken to these work camps...
with the liberation of Germany in 1945, over 11 million people were freed from these work camps, and became known as "displaced persons"...
of the missing 1 million - 4 million people.... many died from disease, harsh treatment, and or starvation... while many of the Jewish prisoners were selected to make the "Aliyah", or the journey down to Israel
