The basic function of the donut chart is similar to the pie chart. It is used to compare the relationship between the whole and the part. Each arc slice represents a category in the whole. It consists of a pie chart hollowed out in the center, and explanatory text is usually placed in the center.

The pie chart is mainly used to show the proportion of different categories. Each fan-shaped slice in the pie chart represents a category. The arc of the fan-shaped slice represents the proportion of the category in the whole. All slices form a whole, that is, 100%.

Pie charts are a controversial type of chart. Some people think that pie charts look difficult to read. Our visual system can only judge that a slice is larger than another, but it is difficult to determine how big it is. In some extreme cases, the slices of the pie chart are similar in size, and the pie chart will lose its functionality. If you have this concern, you can use a bar graph instead.