Natural numbers are positive numbers from 1 to infinity. They do not include the number zero or any negative numbers, fractions or parts of numbers.
They are sometimes called counting numbers:
1, 2, 3, 4, 5, 6 are all natural numbers, as are 27, 435 1,000,000 etc.
Whole numbers are counting numbers but also include zero:
0, 1, 2, 3, 4, 5 etc.
Integers are positive and negative whole numbers and zero:
..... -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 .......
These are not difficult to understand but they can be hard to remember!!
The best way to learn this is to practise - let's get started now!