Also called counting numbers, natural numbers refer to the digits starting from 1, 2, 3, and so on. The number zero is not included if natural numbers are defined as the positive integers only. On the other hand, zero is included if the natural numbers are stated as non-negative integers.

Basically, there is an infinite number of digits that are classified as natural numbers. These digits are neither fractions nor decimals, but instead, are whole numbers. These natural numbers are most commonly used for counting and ordering.

The main difference between integers and natural numbers is that natural numbers are all positive except for zero, which is considered as the only non-positive natural number. The natural numbers are used for a variety of purposes and for different mathematical applications. For instance, it can be used to limit mathematical problems by stating that the answer needs to be a natural number. In addition, this type of numbers is also applied in set theory, which refers to the branch of mathematics that studies and evaluates sets.

Alternatively, natural numbers are used in number theory where they are evaluated independently or as a component of the set of integers. They may be studied independently in order to find out if they behave in a particular way or display specific properties.

Probably one of the most common uses of natural numbers is in counting. Even young kids learn how to count from 0 onwards and can easily learn the difference between 3 and 4, for instance. These children also learn how to express their age through natural numbers.

As they grow up, their knowledge about this type of numbers broadens and they will eventually learn how to manipulate natural numbers. They will learn how to add, multiply, subtract, or divide them. It is only after learning about natural numbers are the concepts of integers and negative numbers introduced.