Which visualization is useful to see multiple data series over the same axis?

The line chart is particularly effective for visualizing multiple data series over the same axis because it allows for the clear comparison of trends and patterns across different datasets over a continuous scale, such as time. Each data series is represented by a distinct line, which enables viewers to easily distinguish between the different series and observe how they relate to one another across the shared axis. This is especially useful when analyzing data changes over time, as the line chart provides a straightforward visual representation of the trajectory of each data series, facilitating quick insights into their relative performances.

In contrast, the area chart displays data in a similar manner to a line chart but fills the area beneath the lines, which can sometimes obscure comparisons between multiple series, particularly when they overlap. Scatter plots are designed for showing relationships between two variables rather than showcasing multiple data series along a single axis. Pie charts are used for depicting parts of a whole and do not provide a comparative examination of multiple series along a common axis. Therefore, the line chart stands out as the most suitable option for visualizing multiple data series effectively.