A whole number is a number without fractions or decimals. Whole numbers include all the positive integers starting from zero, such as 0, 1, 2, 3, and so on. They do not include negative numbers or any numbers with decimal points. Whole numbers are used in everyday counting and ordering. For example, when you count apples or books, you use whole numbers. They are fundamental in mathematics and serve as the basis for more complex concepts, such as integers and rational numbers.