Area charts are much like line charts: the height of the points represent data, and they’re often used for continuous data.
The difference is that area charts have filled areas below the lines in order to distinguish the data more clearly. It is best to stack the areas, one on top of the other, in order to avoid obscuring the area in the back. When this stacking is done however, it is important that the two categories add up to a whole that makes sense. For example, data representing one brand of phone versus another makes a good stacked area chart.
Because area charts emphasize the amount of change over time, they are particularly useful for drawing attention to the total value across a trend.
Like line charts, area charts have an x-axis and a y-axis. The x-axis is usually used for the time period, and the y-axis for the measurement.
If your data does not have a part to whole relationship, you should consider using a line chart instead of an area chart. In a standard area chart, data from one series can be obscured by data from another series.