78/88 as a percentage is 88.64%. This tells you that the fraction is very close to a whole, just a little under one hundred percent. When you see a number like this, you can quickly tell that the value is high.
In everyday terms, 78 out of 88 parts means you have almost all of the pieces. If you were looking at a test score, a result of 88.64% would be considered a solid B+ or an A‑, depending on the grading scale.
Remember that percentages are just another way to show fractions. So whenever you see 78/88, you can think of it as 88.64% and understand it represents a strong majority of the whole.