Infinite divisibility means that you can divide something into smaller and smaller pieces forever without ever reaching an end. Imagine you have a piece of cake. You can cut the cake in half, and then you can cut those halves in half again, and so on. You can keep cutting the pieces smaller and smaller, dividing them into halves or even smaller pieces, but you will never run out of cake!
This concept applies to many things in math and science, like space and time. Scientists believe that space and time are infinitely divisible, which means that they can always be cut into smaller and smaller parts without ever reaching an end.
Another example of infinite divisibility is a number line. On a number line, you can keep dividing the space between two numbers into smaller and smaller parts, and there will always be more numbers to fill in those spaces. This is because there are infinitely many numbers between any two given numbers.
So, in short, infinite divisibility means that some things can always be divided into smaller and smaller parts without ever reaching a limit or end point.