This visualization uses a hierarchical tree layout to display the geographic organization of countries, grouping them by region and subregion under a top-level “World” node. The data is rendered as an interactive SVG graphic, with curved horizontal links connecting parent and child nodes, and text labels displayed at varying font sizes based on depth. Built with D3.js v5, it uses `d3.tree`, `d3.hierarchy`, `linkHorizontal`, and `d3.zoom` to support panning and zooming. Node labels are positioned according to the tree layout’s computed x and y coordinates, with leaf nodes oriented to the right.