All percentages are fractions out of 100. In other words 68% means exactly the same thing as 68/100
you get 2 sets of numbers in a ratio comparison and you only get one in a difference comparison
Equivalent Ratios
A ratio is a comparison between two values. The values can be integers or fractions (ratios).
OK, now I don't know how old you are to be asking some thing like this, but the reason for this is so that when you are comparing some thing in high detail it is can be easier to do it in percent....