A histogram is a graphical representation of a frequency distribution with class intervals or attributes as the base and frequency as the height—pictorial representation in the form of spaced bars to depict numerical data. The histogram is a popular graphing tool. It is used to summarize discrete or continuous data that are measured on an interval scale. It is often used to illustrate the significant features of the distribution of the data in a convenient form. In this section, we shall learn how to represent a grouped frequency distribution graphically. The most common graphic representation is the histogram.