Definition:Natural Numbers/Also known as

Natural Numbers: Also known as
The natural numbers, particularly the set $\set {1, 2, 3, \ldots}$ of non-zero natural numbers, are also known as counting numbers, especially in elementary school.

Some sources refer to them as positive integers, often with the implicit understanding that this means strictly positive integers, without actually being specific.

Some sources refer to the natural numbers as whole numbers, but that term is also often given to the integers.

The term proper numbers can sometimes be seen in popular literature.