Histogram is a graph that is very similar to a bar chart except that bar charts are drawn for qualitative data but histograms are drawn for continuous data. In order to draw the histogram of the data, we usually need to have a large sample. If you remember from previous chapters, the data was classified in to grouped frequency distributions, basically you can think histograms as bar plots of grouped frequency distributions. If you create a grouped frequency distribution of the data, you can easily create the histogram of the same data. Similarly, by looking at a histogram one may easily create the grouped frequency distribution of the data. In bar charts the columns/bars are separated from each other by a convenient distance whereas in histogram the columns/bars are adjacent to each other.