Hexadecimal
/hek-sə-ˈdes-məl/
noun — “base sixteen, where digits stop behaving and letters get promoted.”
Hexadecimal is a positional number system with base 16, widely used in computing as a compact representation of binary data. Each digit represents four bits, allowing long binary sequences to be expressed in a shorter, more readable form using symbols 0–9 and A–F.