What does the arrow indicates in a report summary?

The down arrow ⬇️ indicates the decrease in performance and the up arrow ⬆️ indicates the increase in performance, which is compared to the tickets data with the current time range and the previous same time range.

For example, if you filter report data for "Last 24 hours" then the last 24 hours' data will be compared with the previous 24 hours' data and calculate the change in percentage.