Why does the form ask about the relationship of people in my household to Person 1?

Why does the form ask about the relationship of people in my household to Person 1?

The answers to this question are used to determine household composition. It is also used to determine funding for federal nutrition and education programs, housing programs, and other social services that provide benefits to many U.S. communities. The 2020 Census is the first decennial census that lists same-sex relationships as answer choices on the form.