A chart is a graphic representation of data. Except for pie charts, all charts plot data with reference to a horizontal x axis and vertical y axis. Multidimensional charts sometimes plot data on an additional axis. A pie chart uses the metaphor of the pie as a whole to delineate the relative values of the parts or slices.
You construct a chart by dragging Request items from Elements to one of the data layouts. At least one y axis item must populate an data layout to plot a usable chart.