This example shows a force-directed network of seven named nodes connected by weighted links, with purple circles labeled by green text. The visualization uses D3 v4's `d3.layout.force` to simulate node positions, applying gravity, charge, and link distance, while rendering SVG lines and groups. Data loads from a local JSON file with node names and link weights. Users can click and drag nodes, and the tick handler updates line coordinates and node transforms dynamically. Link thickness encodes weight via `Math.sqrt(d.weight)`, and the SVG canvas is sized 1000 by 500 pixels.