This tree visualization displays COVID-19 statistics by region, from the global root down to individual countries and their cumulative confirmed cases, deaths, and recoveries. The example uses D3 v7’s `d3.tree()` layout and `d3.hierarchy()` to position nodes in a hierarchical structure within an SVG. Leaf nodes carry named values such as “Cumulative Confirmed Cases - 150000,” while branch nodes group continents and countries. The code assigns data-driven properties like `type` and `level` to each node, though the visible rendering draws nodes as white circles with steelblue strokes and gray linking paths.