Why is probability limted to numbers between 0 and 1

This is because 100% is the same as 1. You can't have more than a 100% chance of something happening. 100% means there is no chance it won't happen, so you can't go higher.

You also can't have a negative probability. 0, or 0%, means there is absolutely no chance it will happen.

So, you have to have a probability between "not a chance it will happen" (0) and "not a chance it won't happen" (1).