Three generations of grandparents and grandchildren refer to three generations of grandfathers, fathers and sons. Collateral consanguinity within three generations is a concept relative to lineal consanguinity, which refers to relatives who have blood relations with themselves within three generations. Lineal blood relatives are relatives who have direct blood relationship, that is, relatives who have given birth to themselves and their descendants.

Both parents are included. For example, parents and children, grandparents and grandchildren, grandparents and grandchildren. Collateral blood relatives are relatives with indirect blood relationship, that is, relatives who are not lineal blood relatives but are of the same ancestry. Collateral blood relatives within three generations refer to relatives who have blood relations with themselves within three generations. The three generations here are three generations counting from themselves. Simply put, consider who is the first generation and look up until you are born for the same parents.

From Don Souter's "Dressing Events": "Zhang Jiazhen gives birth to rewards, and enjoys the splendor of life. Since the Zhou Dynasty, three generations of grandparents and grandchildren have been the only one. "

Debut in officialdom for the first time: "Lao Zhao's grandparents and grandchildren are all country people with limited knowledge. How to take care of them?"