First, relatives are different.
Cousins refer to the children of their uncles, and cousins refer to the children of their aunts, uncles and other relatives.
Second, different surnames.
Cousins have the same surname (father's surname), but cousins have different surnames (mother's surname).
Third, the specific classification is different.
Cousins can be divided into "close relatives" and "distant relatives". "Cousin" refers to a cousin who has the same grandfather as himself, while "distant cousin" refers to other cousins who are not the same grandfather but have the same blood relationship. If you are your father's brother or sister or your mother's brother or sister, you are a cousin, otherwise you are a distant relative.
brother-in-law
First, the ancient narrative:
1, Zhao Qingyi's "Cousins in Yu Yu Congkao": "It is customary to take cousins from the same clan. The Book of Rites says that we are called brothers, not cousins. It is said that it was built in the Jin Dynasty. "
2. The title of Liang Qing Zhang Ju records: ... and Emperor Zhao Di, the filial piety in the Book of Northern Qi, said: "Xu Ba is my cousin." Qian Daxin said: "The General Code contains the sentence of Song Dynasty:' Now it is also called' the same clan as my father, Kundi'. People in the Six Dynasties still called a family, but in the Tang Dynasty, the same word was omitted. The Book of Old Tang Dynasty recorded that Zhongzong acceded to the throne, taking his cousin Li Qian as the king of Ji Cheng county. In addition, Zhang Xiancheng invited the elderly and recommended his cousin to pay tribute on his own behalf. "
Second, this explanation:
1, narrow sense:
Grandfather's brothers and sisters are called cousins, that is, uncles' sons. Others call this meaning cousin.
"Cousin's original meaning"-Cousin belongs to the clan category of China's ancient relatives, and it was a big suit within the five clothes in ancient times. The original meaning of cousin is synonymous with subordinate brothers, cousins and uncles.
Before the Sui and Tang Dynasties, this kind of kinship was generally called slave brother, slave brother, and also commonly used as slave brother/slave brother (more common in Wei and Jin books). Synonymous appellation "cousin" appeared in the Jin Dynasty, but it was simply called cousin in the Tang Dynasty, and gradually replaced the previous "sub-father and brother" and "cousin" and became the mainstream appellation.
2. Broadly speaking:
Due to the geographical habits of language and other factors, some people call brothers of the same generation (cousins) who are farther apart by blood as cousins. Others call this meaning a distant cousin.
Cousins in a broad sense include "cousin's original meaning" and "cousin's wrapped meaning", generally referring to "close relatives" and "distant relatives".
References:
Baidu encyclopedia-cousin