Gegroepeerd staafdiagram

Suppose one wants to compare the number of male and female students enrolled in different courses—Statistics, Biology, Physics, and Chemistry. Such comparison of data sets with different categories is visualized using a multiple bar graph. 

Here, the graph contains two groups of bars separated by a gap to indicate two sets of data.

In this case, the black bars indicate the number of male students, and the teal bars represent the number of female students. 

The first set of bars indicates five male and four female students enrolled in Statistics; the second set indicates three male and five female students enrolled in Biology and so on.  

In the multiple bar graphs, one can add any number of bars under various categories, depending on the given number of data sets.

Multiple bar graphs help compare and analyze patterns among several categories. From this bar graph, one can easily answer questions such as which day recorded the highest sale of apples or which is the most popular fruit.