base 2 is a positional numeral system with two as its base. It uses 2 different digits for representing numbers. The digits for base 2 could be 0, and 1.

conversion table

base 2	quaternary (base 4)	base 2	quaternary (base 4)
1	≈ 1	1011	≈ 23
10	≈ 2	1100	≈ 30
11	≈ 3	1101	≈ 31
100	≈ 10	1110	≈ 32
101	≈ 11	1111	≈ 33
110	≈ 12	10000	≈ 100
111	≈ 13	10001	≈ 101
1000	≈ 20	10010	≈ 102
1001	≈ 21	10011	≈ 103
1010	≈ 22	10100	≈ 110