Base-16 (also known as hexadecimal) number system uses 16 symbols to code information. Most commonly, these symbols are, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 'A to F' (or alternatively 'a to f').
Base-3 (also called ternary or trinary) number system uses three symbols to code information. Most commonly, these symbols are, 0, 1 and 2.