base 3 is a positional numeral system with three as its base. It uses 3 different digits for representing numbers. The digits for base 3 could be 0, 1, and 2.
base 9
base 9 is a positional numeral system with nine as its base. It uses 9 different digits for representing numbers. The digits for base 9 could be 0, 1, 2, 3, 4, 5, 6, 7, and 8.