**What is numbering System ?**

Numbering system is **a method for representing numbers using a set of symbols or numbers**.

**Decimal System :**

Most of us are familiar with Decimal System. It is the only numbering system taught in school and people not from programming background or IT do not require to learn any other numbering system.

Decimal numbering is based on number 10, which is called the basis the system. ... In the decimal system these symbols are the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

**Deci means 10 and as we move from right to left each digit has value 10 times greater.**

For eg. 789 = 7 x 100 + 8 x 10 + 9

Or specifically 789 = 7 x 10^{2} + 8 x 10^{1} + 9 x 10^{0}

### Binary System:

Computer internally represent everything as 0’s and 1’s. (on and off). Now to represent anything it has to be converted into 0’s and 1’s and thats the reason Binary numbering system.

As we have seen in decimal there are 10 symbols, in computer only 2 symbols are possible at the lowest level.

Or same thing in other words not only numbers but letters, decimal numbers, pictures, audio, video .... everything has to be converted to 0’s and 1’s and we are in digital world i.e. everything is represented by digits.

Eg. Even voice call which are sent as series of 0’s and 1’s. Video calls are also sent as 0’s and 1’s.

And symbols are 0 and 1.

To represent 13 in binary is 1101.

( 1 x 2^{3} + 1 x 2^{2} + 0 x 2^{1} + 1 x 2^{0} = 8 + 4 + 0 + 1 = 13 )