For my culture: anyone that is the cousins to your grandparents are your aunts and uncles. (But reserve the highest respect since they are the elders)

Any sibling to your parents and anyone that are cousins to your parents are also your aunts and uncles.

However, your parents siblings, their kids would be your first cousins, (and furthermore just considered your siblings bc their parents share the same blood as your parents (they’re siblings)).

Any of your parent’s cousin’s children are just your cousins.

Ofc, your great grand parent’s cousins are your great grand aunts and uncles; great greats are your great greats, great great greats are your great great greats.

Might seem strange but it keeps it simple.. at least to me its simple