The Nuremberg Laws is the name for three (historically: two laws) that were set into practice in Germany in 1935, and that were valid until 1945. They are named after the city of Nuremberg where the legislative assembly met.

They were:

1. Blutschutzgesetz, law concerning the protection of German blood and honor - This law made it illegal for Jews to marry non-Jews. It also made it illegal for these people to have sex with each other. The law provided for long prison terms for the people who did not obey it. Strangely enough, these were only for men, women could go away without prison term (if they told about it).
2.  Reich Citizenship Law : This law basically said that only people of German or closely-related blood could become citizens - in other words: Jews (and some others) could not. All Jews employed by the government had to quit their job. They also lost their right to vote.
3. Reichsflaggengesetz Strictly speaking this is not one of the Nurenberg Laws. It was published with the others though. It made the swastika the official flag of Germany.

On the 14th of November 1935, the Nuremberg laws were expanded prohibiting Roma (Gypsies), Blacks or any of their offspring from engaging in marriage or sexual relations with 'Those of German or German related blood'.