Percentage is a way of expressing a number as a fraction of 100. It's often used to express how much of a total something represents. For example, if you got 80 out of 100 on a test, you could say that you got an 80% on the test.

Percentile, on the other hand, is a way of expressing the relative standing of a value within a set of values. A percentile is a value below which a certain percentage of the values in a set falls. For example, if you scored in the 80th percentile on a test, it means that you scored better than 80% of the other people who took the test.

So, while percentage and percentile both deal with expressing numbers as a fraction of 100, they are used to express different things. Percentage is used to express the proportion of a value to a total, while percentile is used to express the relative standing of a value within a set of values.

It's also important to note that while percentage is always expressed as a decimal between 0 and 1, percentile is expressed as a whole number between 0 and 100.

In summary, the main difference between percentage and percentile is that percentage is a way of expressing a value as a fraction of 100, while percentile is a way of expressing the relative standing of a value within a set of values.