Using variables in your dashboard
If you've inserted variables in your queries, then they can be useful when refreshing dashboards.
Just like in your editor, you can modify the variable's value from dashboard view.
After changing a variable's value at the top of the screen, click the "Refresh" icon to see the changes reflected in your visualization.
Refreshing dashboards with variables
When you refresh a dashboard, any visualization whose underlying query has a variable in it will update, like in the example below.
Refreshing your dashboard is the same as re-running all of its queries. You will only be charged for the queries affected by the variable value change.
Additionally, anyone you share your dashboard with will also be able to change a variable's value and refresh the dashboard.