Example histogram showing five bars. The Y-axis represents the frequency of occurrence of the data and the X-axis the values, an example of possible data. In this case only data from 2 to 4.4 are represented, and they have frequencies from 4 to 68. The range of values on the X-axis is from 2 to 4.4 and the range on the Y-axis is from 0 to 80.