Histogram, also known as quality distribution diagram, is a statistical report diagram, which is represented by a series of longitudinal stripes or line segments with different heights. Generally, the horizontal axis represents the data type and the vertical axis represents the distribution. Histogram is an accurate graphical representation of numerical data distribution. The histogram represents the frequency or quantity of each group by the length of the rectangle, and the width represents the group distance of each group. Therefore, its height and width are meaningful, which is conducive to displaying the statistical results of a large number of data sets. Histogram is a tool that can quickly display the probability distribution of data. It is intuitive and easy to understand, and is deeply loved by data lovers.