79/84 as a percentage is 94.05%. This number tells you that the fraction is just a little shy of a whole, since 100 % would be a perfect 1.
The fraction 79/84 can be thought of as 79 parts out of a total of 84 equal parts. Because the numerator is close to the denominator, the value is high, which is why the percentage is also high.
When you see 94.05% you know that the original fraction represents a very large portion of the whole. It’s useful for quick comparisons, like checking how close something is to being complete or fully achieved.