0.01 of 1 is equal to 1%. This means that if you have a whole (which is represented by the number 1), 0.01 of that whole is 1% of it. In other words, 0.01 is the decimal representation of 1%.
To understand this better, consider that 1% is one part out of a hundred equal parts. So, 0.01 is the same as saying one hundredth of the whole.
For example, if you have 1 dollar, 0.01 of that dollar is 1 cent. Similarly, if you have 1 meter, 0.01 of that meter is 1 centimeter.