Octal number system(Oct) has a base of eight and uses combinations of numerals 0 to 7 to represent any number. 128 is an example of Octal number equal to decimal 10.
Definition : Decimal Number System (Base 10)
Decimal number is the most commonly used number system. It is a base 10 number system, uses combinations of numerals 0 to 9 to represent any number.
It is widely used in everyday life for representing and manipulating numbers in many cultures and scientific applications.