When would you use a 'Card' visual in Power BI?

A 'Card' visual in Power BI is specifically designed to display a single number or value. This makes it especially useful for highlighting key metrics, such as totals, averages, or any important data point that can be represented as a singular figure. For instance, you might use a Card to showcase total sales for the current month, the number of new customers, or the current stock price, providing instant visual recognition of these metrics.

While comparing two sets of data, showing trends over time, or visualizing geographical data would require different types of visuals—such as bar charts, line graphs, or maps—a Card visual's strength lies in its simplicity and focus, effectively drawing attention to one significant number without the distraction or complexity of additional data.