Various different ways by setting up concentration camps or death camps. Death camps were just that. It is where Jews were sent to be killed in great numbers. Most of them put into gas chambers that resembled shower rooms. The ones that didn't go to the gas chambers were sent to other camps. These other camps were called a variety of things like labor camps. Other ways Nazi's would kill these Jews or others being persecuted were by death by shooting, starving the Jews, or working the Jews to death, literally. I believe this was a very in-humane way to have to die and I am glad that it is still not going on