Hexadecimal (or hex) is a base 16 system used to simplify how binary is represented. A hex digit can be any of the following 16 digits: 0 1 2 3 4 5 6 7 8 9 A B C D E F.

Each hex digit reflects a 4-bit binary sequence.

This means an 8-bit binary number can be written using only two different hex digits – one hex digit for each nibble (or group of 4-bits). It is much easier to write numbers as hex than to write them as binary numbers.

For example:

- 11010100 in binary would be D4 in hex
- FFFF3 in hex would be 11111111111111110011 in binary