Area charts are essentially bar charts with the discontinuous breaks removed along the horizontal axis. Data is not broken into discrete bars but is displayed in a continuous ebb and flow as defined against the Y‑axis. Consequently, area charts are particularly useful for emphasizing the magnitude of change over time. In addition, area charts can be used for the same purposes as bar charts.
Because area charts do not break data along the horizontal axis, they are most useful for charting three dimensions of data. The z pane should be used to either project data into a third spatial dimension, or to stack two categories of data in a stacked area chart.