A hierarchical tree visualization displays the world’s countries grouped by continent and subregion, with each node labeled by name. The layout uses D3’s `d3.tree` and `d3.hierarchy` to position nodes, while `d3.linkHorizontal` generates curved connecting paths. Text size decreases with depth, and labels are anchored differently for parent versus child nodes. The SVG rendering supports interactive pan and zoom via D3’s `d3.zoom`, with styling provided by an external stylesheet using the Playfair Display font.