Octal
/ˈɒk-təl/
noun — “base eight, where binary gets bundled into neat little 3-bit packets and pretends that makes life simpler.”
Octal is a positional number system with base 8, using digits 0–7. It is most commonly encountered as a compact representation of binary data, where each octal digit corresponds exactly to a group of three bits. In practice, this makes it a slightly older but still elegant sibling to hexadecimal.
The core idea is simple: binary is verbose. Octal is a compression trick.