China's lineal blood relatives are calculated by "five clothes". Don't use it to determine the distance of blood. The most rigorous definition of Wuyi Brothers is as follows:
Yi Yi brothers, referred to as blood brothers, are half-brothers.
Er Fu brothers, uncles and brothers for short, have brothers as their fathers.
Sanfu brothers, referred to as cousins for short, each other's grandfathers are brothers.
Four brothers, each other's father's grandfather is a brother.
Five Blessingg brothers, each other's grandfather's grandfather is a brother.
Introduction to the relationship between five services
Suits are mainly close relatives, and have a direct inheritance relationship with you, such as your parents, such as your children; Er Fu is mainly a brother and sister, grandson, nephew, uncle and aunt. Your grandfather is the same person; Sanfu is our cousins, cousins, cousins and so on.
Sanfu's relatives, your great-grandfather, that is, your grandfather's father, are the ancestors of everyone; Sifu is farther away, everyone is your grandfather's grandfather, that is, the direct descendant of Gaozu; Five Blessingg is the farthest kinship, and your kinship can be traced back to Tianzu, the grandfather's grandfather's father.
Further out is the so-called five clothes. After five clothes, the blood relationship is actually very weak, and it can only be regarded as the same clan or family. The peers can only be said to be brothers and sisters.