I want to know the answer to the following question:
What makes the definition of a Jew vary slightly?
All the background I'm provided with is that "Generally, in modern secular usage Jews include three groups: people who were born to a Jewish family regardless of whether or not they follow the religion, those who have some Jewish ancestral background or lineage (sometimes including those who do not have strictly matrilineal descent), and people without any Jewish ancestral background or lineage who have formally converted to Judaism and therefore are followers of the religion.". Is that enough to answer the question?
Answer: no