The History of Histograms

In statistics, a histogram is a graphical display of tabulated frequencies, shown as bars. It shows what proportion of cases fall into each of several categories. A histogram differs from a bar chart in that it is the area of the bar that denotes the value, not the height, a crucial distinction when the categories are not of uniform width . The categories are usually specified as non-overlapping intervals of some variable. The categories\bars must be adjacent.