Domains, ranges, and other sets utilize square brackets and/or parentheses to enclose their values. When a square bracket is used, this means the end value of the set nearest to the square bracket is included in the set. When a parenthesis is used, this means the end value of the set nearest to the parenthesis is not included in the set. Sets can either have two square brackets, two parentheses, or a combination of a square bracket and a parenthesis.