An area chart or area graph displays graphically quantitive data. It is based on the line chart. The area between axis and line are commonly emphasized with colors, textures and hatchings. Commonly one compares with an area chart two or more quantities.
The following figures show four examples of symmetrical chart types for two-way tables: the flowchart, the heatmap, the fluctuation diagram and the matrix bubble chart. The last three ones are the simplest in the sense that they reproduce the table grid substituting each cell value by a rectangle or circle with color (the former) or area (the latter) proportional to them.