Answer: They decided to exterminate the Jews, killing millions in what was later termed the Holocaust. The Nazis used poison gas and other means of killing in their extermination camps.
Context/details:
Hitler and the Nazis believed in the supremacy of what they referred to as the "Aryan race" -- which was a term they used for the Germanic peoples. They believed their race was superior to "lesser races" like the Jews, blacks and others. Hitler and the Nazis mounted a campaign in Germany to promote their race over others like Jews and Roma (gypsies), etc.
They enacted what are called the Nuremberg Laws, which were passed at a Nazi rally in Nuremberg in 1935. These laws denied citizenship and other rights to Jewish persons. Examples of such laws:
- The Reich Citizenship Law ruled that only persons of proper ethnic blood were eligible to be German citizens.
- The Law for the Protection of German Blood and German Honour prohibited marriages or any sexual intercourse between Jews and Germans. It even went so far as to say that Jewish persons could not employ female Germans in their household who were under the age of 45 (afraid of something happening and somebody becoming pregnant.)
The Nazi campaign against Jews got even worse from there. In their campaign for a "master race" as well as in support of their World War effort, they used Jews for forced labor in concentration camps. They also used Jewish persons and others they deemed undesirable essentially as laboratory rats for doing unethical medical experiments on them. For example, they'd put persons in a pressure chamber to find out how high an altitude they could let their pilots fly before they'd become unconscious from the altitude and pressure. Others of their experiments were even more gruesome.
Ultimately, there was what the Nazis called "The Final Solution" (in the 1940s), which we now refer to as the Holocaust. Millions of Jews, along with other unwanteds, were exterminated in mass killings.
