What is meant by direct kinship, collateral kinship, and affinity, and what are the degrees of kinship, and to what degree do they extend?

Kinship, in the linguistic sense, denotes closeness in lineage, and a man's relatives are his closest kin. Kinship consists of ascendants (fathers, grandfathers, mothers, and grandmothers, however high), descendants (children and grandchildren, however low), and collaterals (brothers, sisters, and their children; and paternal uncles, paternal aunts, and their children). Parents and children are referred to as "the direct line of descent" (عمودي النسب) because they are the closest to a person. As for affinity (kinship by marriage), it arises due to marriage, and in-laws (أصهار) are the wife's family.