What is the difference between, “father’s brother AND brother’s father”?

The difference between “father’s brother” and “brother’s father” is that one is a direct relative and the other is an indirect relative. Father’s brother is the brother of the father and is thus a direct relative. This means that the father’s brother is the father’s sibling, and thus the father’s brother is the father’s brother. On the other hand, brother’s father is the father of the brother and is thus an indirect relative. This means that the brother’s father is the brother’s parent, and thus the brother’s father is the brother’s father. In other words, the father’s brother is the brother of the father, while the brother’s father is the father of the brother.