59/75 as a percentage is 78.67%. This is the rounded value you get when you change the fraction into a percent with two decimal places.
The fraction 59/75 is a bit bigger than three‑quarters. If you picture a pizza cut into 75 slices, taking 59 of those slices would leave you with about three‑quarters of the whole pizza.
Knowing the percent makes it easy to compare. For example, a test score of 59 out of 75 points is the same as getting 78.67%, which is often enough to be considered a solid “C” or “B‑” in many schools.