What does it mean that children are not in the family in the comparative review of younger population?

In the comparison and review of young people, children are not in the hukou, and hukou refers to household registration.

Hukou book is a public certificate book that registers and issues certificates to natural persons on a household basis. The recorded items include the natural person's name, date of birth, relatives and marital status. It is the basic legal document to determine the legal status of natural persons as civil subjects.

Ancestral place refers to the birthplace of grandparents. Some people have left the birthplace or hometown of their ancestors, and their descendants still trace back to the birthplace or hometown of their ancestors (that is, ancestral home) as their birthplace. Generally speaking, ancestral home refers to my grandfather's birthplace.

Extended data:

Household registration is not necessarily a person's native place, but it is different from someone's native place, especially in economically developed areas and some new places that started construction after the founding of New China and developed rapidly in modern times.

The native place of a large number of people is not their domicile, but their native place or ancestral home. These people generally moved here from other places after the reform and opening up, in the era of planned economy in China, according to the requirements of the country at that time. According to the tradition of China for thousands of years, native place is an expression of ancestral home, which is the difference between household registration and native place.