A frequency distribution, sometimes called a histogram distribution, is a representation that displays the number of observations within a given interval. It is used to show the empirical or theoretical frequency of occurrence of each possible value in a data set, often recorded in a frequency table. Frequency distributions of categorical data are typically presented using a bar graph.

In the case of numerical data, the graphical representation of a frequency distribution is called a histogram.

Depending on how a data set is distributed, its histogram can have different shapes. The most common types of distributions are symmetric frequency distribution and skewed frequency distribution.