What is "octal"

Sistema Octal is a numbering system based on 8, meaning it uses 8 symbols for the quantity representation.

In the west, these symbols are the Arabic numerals: 0, 1, 2, 3, 4, 5, 6, 7.

Octal has been widely used in computer science as a more compact alternative to binary in machine language programming. Today, the system hexadecimal is more used as an alternative to torque.

Currently, it can be used to assign permissions^english to files or directories on systems UNIX.

Example of octal number conversion 354 to the decimal system:

(3 * 8²) + (5 * 8¹) + (4 * 8⁰) = 236 _decimal

Source:

Wikipedia - Octal System