The Octal Number System is a base-8 numeral system that uses digits from 0 to 7. It is often used in computing and digital electronics because it can represent binary numbers more compactly. Each octal digit corresponds to three binary digits (bits), making it easier to read and write large binary numbers. In the octal system, the value of each digit is determined by its position, similar to the Decimal Number System. For example, the octal number 17 represents 1 \times 8^1 + 7 \times 8^0, which equals 15 in decimal. This system simplifies certain calculations and is useful in various programming contexts.