Why should we use 0 and 1 in binary number?

Question

Others are also available for eg. 2 and 4
1 and 3
2 and 1
And so on.......
But why it is so?

Answer 1

Hello! I saw that you also tagged programming in your question, in fact, binary numbers or bases in general is a concept originally belonging to mathematics, introduced by Leibniz in the 16th century.
Think of base 10 numeral system, that's the daily use system, how many digits do we actually use? There's 9 and 0 of course: 0 1 2 3 4 5 6 7 8 9.
And every number you can think of can be written as a combination of those.
The same goes for binary system, the base is 2, so you get to use only 0 and 1.
In general, if a numeral system is at base b, the number of available digits are b-1.

Answer 2

As you can see a 0 basically represents zero value, that can be used to declare a not,empty,null position. While we have a positive number 1 that represents an active state. And every number i.e 0-9 can be expressed in terms of 0 and 1.