You can quickly access various statistics related to your current selection and entire scene.
To use the viewport statistics display:
You can customize the viewport statistics by turning on and off options on the Statistics panel of the Viewport Configuration dialog. The following statistics reflect all options turned on.
The first column lists the statistics for the entire scene, while the second only refers to the selected objects.
Displays the number of polygons in the scene and selection.
Displays the number of triangle faces in the scene and selection.
Displays the number of edges in the scene and selection.
Displays the number of vertices in the scene and selection.
The frames per second displayed in the viewport.