A Power BI dashboard is a single page, often called a canvas, that tells a story through visualizations. Because it's limited to one page, a well-designed dashboard contains only the highlights of that story. Readers can view related reports for the details.
Advantages of dashboards:
Dashboards are a way to monitor your business and see all your most important metrics at a glance. The visualizations on a dashboard can come from one underlying dataset or many, and from one underlying report or many. A dashboard combines on-premises and cloud data, providing a consolidated view of data.
A dashboard isn't just a pretty picture. It's highly interactive, and the tiles update as the underlying data changes.
Datasets in import mode and composite datasets that combine import mode and DirectQuery mode don't require a separate tile refresh, because Power BI refreshes the tiles automatically during each scheduled or on-demand data refresh.