A force-directed network graph shows global airline routes between seven major airports, with nodes colored by region and labeled with city and airport code. The example uses D3's `d3.forceSimulation` to drive a physics-based layout, applying `d3.forceLink` for edge distances, `d3.forceManyBody` for repulsion, and `d3.forceCenter` to keep nodes centered. Links are drawn as SVG lines, nodes as circles with `drag` interaction, and labels as text elements.