hexadecimal
Writing numbers in base 16 with digits 0-9 and A-F; each hex digit stands for exactly four bits.
Hexadecimal is base-16 positional notation, conventionally prefixed 0x; one hex digit corresponds to one 4-bit nibble.
Examples
0x2Fis 2 × 16 + 15 = 47, and its bits are0010 1111: one hex digit for every four bits.
See also