Definition of Octal Number System: The octal number system is the base-8 number system, and uses the digits 0 to 7. That is to say 10octal represents eight and 100octal represents sixty-four.
In the early phase of modern computer development, 6-bit, 12-bit binary words were vastly used. Octal numbers were ideal for abbreviating those words. In the current times, however, 32-bit, 64-bits and even bigger binary words are used in computers.
The binary (or base-2) number system uses only two digits; that is 0 and 1. This system makes the foundation of modern digital devices work. We know that the computers, calculators, watches and other digital devices all work on electricity. The electric current can have two states - either it is there or not there! This binary state of the electricity is represented with 0 and 1 of the binary number system. When the current is there, the state is represented by 1 and when it is not there, the state is said to be 0.
The binary system may also be understood with other nomenclature such as true/false, on/off and yes/no.
Definition of a Binary Number: A binary number is a number expressed in the base-2 numeral system or binary numeral system, which uses only two digits: typically '0' (zero) and '1' (one).