Variables can either be discrete and noncontinuous (race, sex), or are treated as though they were discrete and noncontinuous (i.e., age groups rather than age intervals along an axis).

The length or height of each bar is proportional to the frequency of the event in that category.

A vertical bar chart differs from a histogram in that the bars are separated, whereas, in histograms the bars are joined.

Scale breaks should never be used with bar charts since this can lead to misinterpretation when comparing the magnitude of different categories.