Which numerical system uses base 8?

The numerical system that uses base 8 is known as the octal system. In the octal system, there are eight unique digits used to represent values: 0, 1, 2, 3, 4, 5, 6, and 7. Each digit's position corresponds to a power of 8, similar to how in the decimal system (base 10) each digit's position corresponds to a power of 10.

In contrast, the binary system operates on base 2, utilizing only 0 and 1 as its digits. The decimal system, which is the most commonly used numerical system, utilizes base 10 with digits ranging from 0 to 9. The hexadecimal system is based on 16 and employs sixteen different symbols, which include the digits 0 through 9 and the letters A through F to represent values from 10 to 15.

Understanding the octal system is important in various computing contexts, especially in older programming and computer systems where octal representation simplifies binary data. Thus, the correct answer, referring to a system that employs base 8, is indeed the octal system.