This visualization displays the hierarchical structure of world countries organized by continent and subregion. The data is loaded from a JSON file containing nested nodes for regions and individual nations. The tree layout positions nodes horizontally, with curved links connecting parent and child elements. Users can pan and zoom using D3’s zoom behavior. The visualization is rendered as an SVG using `d3.tree`, `d3.hierarchy`, and `linkHorizontal` for path generation, with text labels sized by node depth.