A link tree visualization displays world countries as nodes connected by directional links, with arrow markers indicating flow direction. The SVG rendering positions nodes at fixed coordinates from a JSON data file and offsets them vertically for link path generation. Using d3.json, d3.linkHorizontal, and D3 v5 selection joins, the visualization draws curved horizontal paths with blue strokes and circles for nodes. The code includes a marker definition for arrowheads, though no interactive behavior or force simulation is currently active.