The question is really weird, because i cant put what i want to ask in one question.

What i am trying to ask is

Primary brackets: when you want to show (x+y)-(x+y), you use (), may i ask what this name is? or is it just "bracket"?

Secondary brackets: when you want to group it up more [(x+y)-(x+y)]-[(x+y)-(x+y)], you use [], square brackets.

Tertiary brackets: when i try to group it up more, i use ?[(x+y)-(x+y)]-[(x+y)-(x+y)]?-?[(x+y)-(x+y)]-[(x+y)-(x+y)]?

what do i put at the question marks?

Do brackets stop at secondary? or are there more than that? If so, how many more are used officially?