A hierarchical tree chart displays the nested structure of world regions and countries, with each node labeled by name. The visualization uses D3 v5’s `tree` layout and `linkHorizontal` generator to draw curved paths between parent and child nodes, while `zoom` enables interactive panning and scaling of the entire diagram. Text size decreases with depth, and labels are positioned to align with leaf nodes or center over branching nodes, all rendered as SVG elements within a fixed, full-viewport canvas.