The smallest natural number is 0. 0 is neither a positive number nor a negative number, it is an integer and the smallest natural number;

Natural numbers are used to measure the number of things or to indicate the order of things. That is, the numbers represented by the numbers 0, 1, 2, 3, 4, ... representing the number of objects are called natural numbers, and natural numbers start from 0, one by one, forming an infinite group. Natural numbers are ordered and infinite. Divided into even and odd numbers, composite numbers and prime numbers.

Integers include natural numbers, so natural numbers must be integers and non-negative integers.

Natural numbers play a great role in daily life, and people use them widely. Natural numbers are the earliest numbers in human history, which are widely used in counting and measurement. People often use natural numbers to mark or classify things, such as bus routes, house numbers, postal codes, etc.

Natural numbers are integers (including positive integers and zeros), but not all integers are natural numbers. For example,-1 -2 -3 ... is an integer rather than a natural number. Natural numbers are infinite.