How did the government decide if someone was Jewish during the holocaust?

During the Holocaust, the Nazi regime used a combination of racial laws, ancestry, and self-identification to determine if someone was considered Jewish. The Nuremberg Laws of 1935 defined Jews based on their ancestry, specifically anyone with three or four Jewish grandparents, regardless of their religious beliefs or practices. Additionally, individuals could be labeled as Jewish if they identified as such, and this classification often led to severe persecution and discrimination. The system was bureaucratic and dehumanizing, relying on official records, community reports, and personal testimonies.