The Enable Auto Refresh setting lets you enable the auto-refresh functionality in the current dashboard.
The Interval Settings lets you define recurring intervals during when auto-refresh should happen in the dashboard.
The Event Trace shows the event traces during the auto-refresh process in the dashboard.
To explore the sample functionality, enable the checkbox in the Properties window and click Apply. Now, the auto-refresh gets enabled to occur every 30 seconds in the dashboard fetching the latest data from the data source. During the auto-refresh process, the events triggered will get logged in the trace window.