Mrs. Terry's class has 28 students. The class includes 12 boys. What is the ratio of girls to boys? (remember to simplify)
3:4
3:7
4:3
7:3

The major difference is that a histogram is only used to plot the frequency of score occurrences in a continuous data set that has been divided into classes, called bins.  bar charts, on the other hand, can be used for a great deal of other types ofvariables  including  ordinal  andnominal  data sets.