The following map represents the city of Ames, Iowa, and more specifically the distribution of homes sold from 2006 to 2010. We can see that the coloring was done based on the 28 districts of the city and by positioning the cursor you can see it macro area to which the city belongs. The size of the circles corresponds to the selling prices of the houses, so the larger the circle, the higher the selling price. Finally, by clicking on each point you can see all the attribute values of that particular instance.
I recommend viewing the map by setting the OpenStrettMap view type, which can be found by clicking on the icon under the Zoom buttons.