A collapsible tree charts the hierarchical relationship of world continents, regions, and countries, parsed from a JSON dataset. The visualization uses D3 v5’s `tree` layout and `hierarchy` to structure the data, then renders nodes as text labels and links as horizontal paths via `linkHorizontal`. A zoom behavior enables panning and scaling of the SVG canvas. Labels adjust font size based on depth, with intermediate nodes centered and leaf countries left-aligned, styled with a serif font and white text shadow.