data series
A data series (or data set) is a set of related values that are plotted on a chart (for example, monthly sales figures for a particular region). How a data series is represented varies depending on the kind of chart:
Column charts and bar charts: A data series is represented by a series of bars in 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 and donut 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.