The following introduction is as supplied by Pen and Sword:
Following the 1940 invasion of Poland, the Nazis established ghettos in cities and towns across the country with the initial aim of segregating and isolating the Jewish community. These closed sectors were referred to as Judischer Wohnbezirk or Wohngebiet der Juden (Jewish Quarters).
This is partial text from the full article (usually with photos) at https://armorama.com/news/the-ghettos-of-nazi-occupied-poland