Think of a big pie, apple/blueberry the choice is yours. And think of the whole pie like 100%. Then each slice is a proportion.
So if you take a great big slice of pie e.g. half (1/2) the whole pie then you have taken 50%.
If you take a smaller piece, say you cut the pie into three then each piece is 1/3 of the pie and is 33.3%
If you cut the pie into 4, each slice is 1/4 and worth 25%.
I hope that helps you to understand the underlying concept... if you have a specific question you want to ask then I'll be happy to help - it's hard to know exactly what you need to know from the question you have asked.