What are cousins? How are they considered cousins?

Cousins ??refer to the sons of one's uncles, and cousins ??can be divided into "brothers" and "distant cousins". "In-laws" refer to cousins ??who have the same grandfather as oneself, while "distant cousins" refer to other cousins ??who are not the same grandfather as oneself but are from the same bloodline as oneself.

"Cousin", also known as "middle cousin", refers to the children of one's father's sisters or mother's brothers and sisters. There are also cousins ??who are distantly related. If they are the children of their father's siblings or their mother's siblings, they are biological cousins, otherwise they are distant cousins.

Whether they are "cousins" or "cousins", they all involve blood relationships, so I might as well tell you about them.

Blood relations are divided into two types: direct blood relations and collateral blood relations.

Direct blood relatives are relatives who have a direct relationship, that is, relatives who gave birth to themselves and their descendants. Both father and mother are included. Examples include parents and children, grandparents and grandchildren, grandparents and grandchildren, etc.

Collateral blood relatives are relatives with indirect blood relationships, that is, relatives who are not direct blood relatives but have the same blood source as themselves. Collateral blood relatives within three generations are relatives who are from the same blood lineage as oneself within three generations. The three generations here are the three generations counted as one generation starting from oneself. For example: 1. My brothers and sisters are from the same origin as my parents. I am the first generation and my parents are the second generation. Therefore, my brothers and sisters are collateral blood relatives within the second generation; 2. Uncles, aunts, and cousins. I share the same origin with my grandparents, I am the first generation, my father, uncles, and aunts are the second generation, and my grandparents are the third generation, and these relatives are all from the third generation, so I and my uncles, aunts, and cousins Sisters are collateral blood relatives within three generations; 3. Uncles, aunts, and cousins ??are from the same source as my maternal grandparents. I am the first generation, my mother, uncle, and aunt are the second generation, and my maternal grandparents are the third generation. These relatives all originate from the third generation, so I, my uncle, aunt, and cousins ??are also collateral blood relatives within three generations. This kind of expression can be said to be very clear in writing and easy to understand, but it is indeed difficult for people who are new to it to understand it. It is better to understand it slowly.