This map visualization displays global population estimates for 2018 using circles overlaid on a geographic projection. The code uses d3.geoPath with a natural Earth projection to render country outlines, while d3.scaleSqrt determines circle sizes based on population data from the UN Population Estimates dataset. Interactive features include zoom via d3.zoom and hover tooltips showing regional names and population counts. A custom size legend with d3.ticks explains the circle scaling, and countries with missing data appear in a distinct color.