Taxonomy of Data Visualization Methods - Data Visualization: A Successful Design Process - page 133

Area chart
Data variables : 1 x quantitative-interval, 1 x categorical, 1 x quantitative-ratio.
Visual variables : Height, slope, area, color-hue.
Description : As you can see in the following example, a number of visual properties
are involved in area charts. The vertical position and connecting slope of the horizon
(like a line chart) shows the progression of the values over time and the color area
underneath the chart helps to emphasize these changes. Unlike a standard line chart,
an area chart should have the y axis starting at zero to ensure the area judgment is
being interpreted accurately.
Horizon chart
Data variables : 1 x quantitative-interval, 1 x categorical, 2 x quantitative-ratio.
Visual variables : Height, slope, area, color-hue, color-saturation/lightness.