What are brackets in algebra?

There are both "square" and "curly" brackets used in algebra. They are [] and {} respectively in type. Usually square brackets are used to group smaller numbers of terms than curly brackets, and even square brackets are used only to group quantities some of which are in parentheses. Thus a suitable use example would be {[(a

• b)(c + d) - a2]/[(fg + hj)/[k(l/m)]}. Larger square brackets are

also used to set off numbers in matrix format.