What does the trend line in a sparkline chart indicate?

The trend line in a sparkline chart is used to visualize the variation of data over time, making it a powerful tool for identifying patterns, trends, and changes within a dataset. Sparkline charts are designed to provide a compact representation of data, often in a small space, allowing viewers to quickly assess information without the clutter of axes and labels. By depicting the highs and lows of data points in a continuous line format, the trend line effectively highlights the overall trajectory and fluctuations of the data, enabling users to discern trends and patterns at a glance. This visual representation is particularly useful for monitoring metrics over specific time periods, facilitating quick insights into performance or changes in trends.