Rational numbers and whole numbers are related, but they’re not the same. Whole numbers are the numbers 0, 1, 2, 3, and so on—basically, all the positive numbers including zero without any fractions or decimals. On the other hand, rational numbers are numbers that can be expressed as a fraction of two integers (like 1/2 or -3/4).
Not all rational numbers are whole numbers. For example, 1/2 and -3/4 are rational but not whole numbers since they aren’t whole and positive. However, all whole numbers are rational numbers because you can write them as a fraction—like 5 can be written as 5/1.
So to sum it up: some rational numbers aren’t whole numbers, but all whole numbers are rational numbers!