Hexadecimal:

in hexadecimal, each digit has 16 possible values, beginning with 0 as the lowest possible value, and ending with F as the highest possible value, each alphanumeric digit is used to represent 4 bits of binary code, this is called base 16, or Hexadecimal, or simply Hex, here is an example using 2 digit hexadecimal to represent 8 bit binary, counting from 00 to 20 in hex,

0000,0000 = 00

0000,0001 = 01

0000,0010 = 02

0000,0011 = 03

0000,0100 = 04

0000,0101 = 05

0000,0110 = 06

0000,0111 = 07

0000,1000 = 08

0000,1001 = 09

0000,1010 = 0A

0000,1011 = 0B

0000,1100 = 0C

0000,1101 = 0D

0000,1110 = 0E

0000,1111 = 0F

0001,0000 = 10

0001,0001 = 11

0001,0010 = 12

0001,0011 = 13

0001,0100 = 14

0001,0101 = 15

0001,0110 = 16

0001,0111 = 17

0001,1000 = 18

0001,1001 = 19

0001,1010 = 1A

0001,1011 = 1B

0001,1100 = 1C

0001,1101 = 1D

0001,1110 = 1E

0001,1111 = 1F

0010,0000 = 20

At this point I think it prudent to note that, 1 hexadecimal digit is commonly called a nibble, and pairs of 2 hexadecimal digits are commonly called a Byte,

up next: BCD, or Binary Coded Decimal,