A histogram is a chart that groups numeric data into bins, displaying the bins as segmented columns. They’re used to depict the distribution of a dataset: how often values fall into ranges. The histogram was first introduced by Karl Pearson.

To construct a histogram, the first step is to bin the range of values, and then count how many values fall into each interval. A rectangle is drawn with height proportional to the count and width equal to the bin size, so that rectangles abut each other.