Notice there are four data points in that category, and on this frequency histogram, the height of the bar is indeed four. So this is a nice way of looking at a distribution, but you might be more concerned with what percentage of my data falls into each of these categories. And that becomes especially interesting if we have many, many, many, many data points. And if we had 1,600,432,507 data points, well, just knowing the absolute number that fit into each category isn't so useful. The percent that fits into each category is a lot more useful. And so for that, we could set up a relative frequency histogram. So notice, this is representing the same data.