The number zero is not regarded as natural number.
To understand the concept of zero, let us consider the following example :
Suppose we have to distribute 8 pencils equally among three children. After distributing 2 pencils to each child, we are left with 2 pencils. Whereas if we have to distribute 6 pencils equally among 3 children, we are left with no pencils or zero pencils as remainder.
Thus, zero pencils means absence of pencils or simply no pencils. We represent the number by the symbol 0. Thus, 0 represents the absence of item being referred to or nothingness or emptiness.