data series
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 (colour or texture).
Stacked charts: A data series is represented by the portions of bars with the same fill (colour 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 and doughnut 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.