What did the Nuremberg Laws decree?

The Nuremberg Laws were established in Germany on September 15, 1935. They were a set of antisemitic laws which severely limited the rights and freedom of Jewish people living in Germany. The Nuremberg laws were broken up into two main sections.
The first section was the Reich Citizenship Law. This established who was considered protected by the German government. The Reich Citizenship Law decreed citizens must be German or of German blood and that nationality was determined by the Reich itself. Only people who were considered to be fully German were granted full political rights and protection.
In November of 1935, the Reich Citizenship Law went one step further and also determined who was considered to be Jewish. Even people who didn't practice Judaism but had a Jewish grandparent were still deemed partially Jewish under the new law and were subject to the punishments and cruelty that came along with it.  
The second section of the Nuremberg Laws was the Law for the Protection of German Blood and Honor. This law stated that in order to keep the German bloodlines pure, German citizens were forbidden from marrying people of Jewish descent. Also, people who were currently married to Jewish spouses were encouraged to divorce them and find a more suitable partner. 
Eventually, the Nuremberg Laws grew into what would become the Holocaust.
https://encyclopedia.ushmm.org/content/en/article/the-nuremberg-race-laws