This tree graph visualizes patient data from a sample dataset, using a hierarchical layout to show each patient’s name, ID, gender, and age as leaf nodes. The visualization employs the D3.js v7 library with an SVG rendering approach, utilizing the `d3.tree` layout and `d3.hierarchy` to structure the data. Links are drawn with `d3.linkHorizontal`, while circles and text labels are styled via CSS. The code computes node positions and connects them to display the tree structure.