To make a chart easier to read, you can add series lines (series lines: In 2-D stacked bar and column charts, lines that connect the data markers in each data series that are used to emphasize the difference in measurement between each series.), drop lines (drop lines: In line and area charts, lines that extend from a data point to the category (x) axis. Useful in area charts to clarify where one data marker ends and the next begins.), high-low lines (high-low lines: In 2-D line charts, lines that extend from the highest to the lowest value in each category. High-low lines are often used in stock charts.), or up-down bars (up-down bars: In line charts with multiple data series, bars that indicate the difference between data points in the first and last series.). Series lines connect the data series (data series: Related data points that are plotted in a chart. Each data series in a chart has a unique color or pattern and is represented in the chart legend. You can plot one or more data series in a chart. Pie charts have only one data series.) in 2-D stacked bar and column charts. Drop lines are available in 2-D and 3-D area and line charts. High-low lines and up-down bars are available in 2-D line charts. Stock charts already have high-low lines and up-down bars.
Series lines on a stacked column chart