Overview is the page that will give you a quick summary of your campaigns.
You can select which metrics you want to see and can compare their performances in terms of the time period you choose.
If you like to visualize the insights, just scroll down the page. You will see a graph on the left-hand side, and a map on the right-hand side.
By applying the graph, you can review two insights that you select from the drop-down menu in terms of gender or device categorization. And for the map part, you can see selected insights when you mouse over on a particular area.
There you go!