What is the relationship between brother and sister?

Brother and sister are brother and sister. Brothers and sisters are the collective names of brothers and sisters, that is, people who are related by blood.

A brother is a brother, and a sister is a sister. Brother and sister refer to two people who are related by blood, a man and a woman are peers. Men are older than women, or almost unrelated. Men are older than women and can also be called brothers and sisters.

Extension: brothers, that is, brothers and younger brothers; Sister, sister, that is, sister and sister; Sister refers to sister.

Brothers and sisters:

Brothers and sisters, relational appellation, refers to brothers, brothers and sisters, but does not mean that parents are children other than themselves. Brothers and sisters can be divided into blood brothers and sisters, the former includes blood brothers and sisters, and the latter includes adopted brothers and sisters, and can also be divided into half-brothers or half-brothers.