A tree graph displays hierarchical death rates for ten cancer types across countries (United States, Canada, Japan, China) for 2019. Each branch represents a country and cancer type, with leaf nodes showing the number of deaths. Using D3 v6’s `d3.tree()` layout on an SVG canvas, nodes are positioned vertically, with blue internal nodes and red leaves. The data originates from a CSV file and is structured with a parent ID function that splits the hierarchical ID string.