This network graph visualizes the relationships between entities in a hospital management system, such as patients, nurses, doctors, and reports. The D3.js `forceSimulation` with `forceLink`, `forceManyBody`, and `forceCollide` physics arranges nodes, while SVG `<line>` elements with markers show directed links. Nodes are interactive: users can drag them, and hovering highlights the node with a thick stroke. The data comes from `data.json`, which defines nodes with group assignments and edges with relationship types. The visualization uses D3 v6 and renders entirely with SVG elements.