Ans - Parity.
Parity is a mathematical term that describes the property of an integer's inclusion in one of two categories: even or odd. An integer is even if it is 'evenly divisible' by two (the old-fashioned term "evenly divisible" is now almost always shortened to "divisible") and odd if it is not even.[1] For example, 6 is even because there is no remainder when dividing it by 2. By contrast, 3, 5, 7, 21 leave a remainder of 1 when divided by 2. Examples of even numbers include −4, 0, 8, and 1738. In particular, zero is an even number.[2] Some examples of odd numbers are −5, 3, 9, and 73. Parity does not apply to non-integer numbers.
A formal definition of an even number is that it is an integer of the form n = 2k, where k is an integer;[3] it can then be shown that an odd number is an integer of the form n = 2k + 1. This classification applies only to integers, i.e., non-integers like 1/2, 4.201, or infinity are neither even nor odd.
