This network graph visualizes an electricity infrastructure system, showing power plants, substations, and distribution centers as colored nodes with links labeled by capacity in megawatts. The D3.js visualization uses `d3.forceSimulation` with `forceLink`, `forceManyBody`, and `forceCenter` to position connected elements, while nodes are colored by group type. The SVG renders straight lines for connections, rotated text labels for capacities, and node labels that display on mouseover. The underlying `data.json` supplies the node and link data with capacity values.