The World Countries Tree visualizes the hierarchical structure of continents, regions, and countries using a horizontal dendrogram layout. It renders the data as SVG paths with curved links connecting parent nodes to their children. The implementation uses D3 v5 APIs including `d3.tree`, `d3.hierarchy`, and `d3.linkHorizontal` to compute the layout and generate the connecting paths, while styling employs the Playfair Display font and a teal stroke color against a clean background.