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