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

base 35 is a positional numeral system with thirty-five as its base. It uses 35 different digits for representing numbers. The digits for base 35 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, and y.