My father's brother is called "Uncle". The relationship with uncles and aunts is an uncle's relationship. Because uncles and aunts are also called master and mistress.
It could be uncle and nephew. Uncle and nephew's relations include uncle and nephew. But uncle and nephew only refers to the relationship with his uncle and aunt.
Father's brother is called "uncle". The relationship with uncles and aunts is an uncle relationship.
The relationship between uncle and nephew, uncle (aunt) and nephew (niece).
His brother's people (nephew; ; Brother's son), or nephew, nephew, nephew.
His brother's daughter (niece; ; Brother's daughter), or niece.
The reproduction and survival of human beings are interlinked, and all ethnic groups have a kinship appellation system to express the relationship between family members. Kinship appellation refers to the appellation that takes oneself as the center and determines the relationship between relatives and themselves. It is the appellation that relatives call each other on the basis of blood relatives and in-laws. It is a sign to determine the relationship between relatives and themselves with themselves as the axis.