Pie chart is a graphic representation of quantitative information by means of a circle divided into sectors, in which the relative sizes of the sectors correspond to the proportions of the quantities. Essentially, this chart shows the percentile relationship between parts as compared to the whole.
Each segment is representative of the top values of the report dimension you’ve decided to run. Smaller values are grouped into 'Other' segment. The pie chart adjusts to display the necessary segments to match the way the data is divided.
If you mouse over a specific segment of the circle or pie, a statistical bubble appears with information about the metric you have chosen and the dimension of the report.
The color legend to the right of the pie chart identifies the segment on which the pie chart is reporting. If a dimension in the legend is hovered, the pie chart glows for that dimension, making it easier to identify.
In addition, to get a deep-dive view of how a certain dimension is performing over a particular time period, click on any segment of the pie chart. The timeline graph for the dimension you selected will load.