This visualization displays the hierarchical structure of world countries organized by continent and subregion using a tree layout. It reads a nested JSON data file and renders the hierarchy as horizontal links with country names positioned along the branches using SVG elements. The implementation uses D3 v5's `tree()` and `hierarchy()` functions, with `linkHorizontal()` for path generation and `zoom()` for panning and scaling. Text styling employs Playfair Display with white shadows for readability against the teal link strokes.