A data series is a set of related values that are plotted on a chart.
In Numbers, data series are represented differently in different kinds of charts:
Column charts and bar charts: A data series is represented by a series of bars with the same fill (color or texture).
Stacked charts: A data series is represented by the portions of bars with the same fill (color or texture).
Line charts (also called graphs): A data series is represented by a single line.
Area charts: A data series is represented by an area shape.
Pie charts: Only a single data set (the first data point in each series) is represented on the chart.
Scatter charts: Two columns of data are used to plot values for a single data series. Each pair of values determines the position of one data point.
Bubble charts: Three columns of data are used to plot values for a single data series. Each triplet of values determines the position and size of one data point (bubble)—the first two values (x and y) determine the position (or coordinates) of the bubble, and the third value (z) determines the size of the bubble.