This example visualizes an organizational hierarchy as a tree graph, with nodes representing employees and colored by role (CEO in green, CTO in blue, CFO in orange, and HR Manager in red). The data is loaded from a CSV file via `d3.csv`, then transformed into a hierarchy using `d3.stratify` and laid out with `d3.tree`. The resulting SVG is rendered using `d3.linkHorizontal` for curved links between nodes, with each node displaying a circle and the employee's name as text.