A hierarchical tree visualization displays countries organized by continent and subregion, with the world as the root. The layout positions nodes horizontally by depth, and text size decreases with each level. D3 v5’s `tree` layout, `hierarchy`, and `linkHorizontal` generate the SVG paths and labels, while a `zoom` behavior enables pan and scaling. The data comes from a JSON file, and text styling uses the Playfair Display font.