What are "data series" in Excel charts?

In Excel charts, "data series" refer to the collections of related data points that are displayed in the chart. Each data series represents a specific set of values that correspond to the values plotted along the axes. For example, in a line chart, each line might represent a different data series, such as sales figures for different years or different product categories.

Data series are essential because they allow users to visualize trends, comparisons, and relationships within the data. By defining distinct data series, Excel enables users to focus on specific aspects of the data and make decisions based on visual comparisons.

The other concepts mentioned in the choices, such as visual styles, types of charts, and legends, do not accurately define what data series are. Although they are related to the overall presentation and understanding of the chart, they do not form the core definition of what constitutes a data series in Excel charts.