Connects data points with straight lines to show trends over time. One of the most fundamental chart types for visualizing continuous data and identifying patterns, peaks, and troughs across a time series.
NASA's Shrinking Slice — Budget as % of Federal Spending (1960-2025)
Best for
- Showing trends over time
- Comparing multiple time series on the same scale
- Identifying peaks, valleys, and inflection points
Avoid when
- You have only a few categories — use a column chart instead
- Data is not continuous or sequential
- You need to emphasize volume or magnitude — use an area chart