Definition of Hexadecimal Number System: The hexadecimal (also base-16 or simply hex) number system is a positional numeral system that represents numbers using a base of 16. Unlike the decimal system representing numbers using 10 symbols, hexadecimal uses 16 distinct symbols, most often the symbols '0–9' to represent values 0 to 9, and 'A–F' (or alternatively 'a–f') to represent values from 10 to 15.
Base-3 (also called ternary or trinary) number system uses three symbols to code information. Most commonly, these symbols are, 0, 1 and 2.