I assume there's choices if you started the question with "Which".
But I kind of follow what your asking.
Hitlers plan to eliminate all Jews during World War II started by having all Jews wear a star-like patch indicating they are Jews. They were later moved to confined towns called "Ghettos". After that, many were picked to be sent to concentration camps located around Germany. Some camps were labor camps while others were execution camps.
Hope this brings you to a good understanding of the subject.