Natural Numbers: The set of numbers 1, 2, 3, 4, ... Also called counting numbers.
There are many different ways we can classify numbers. In fact, many of the classifications are subsets of other classifications. For example, the set of natural numbers differ from the set of whole numbers by excluding 0. Therefore, the set of natural numbers is a subset of the set of whole numbers.
The following table gives depictions of how the classifications relate:
Together the rational and irrational numbers form a larger set of numbers called the Real Numbers. Integers, whole, and natural numbers are rational but NOT irrational.