Three groups of colored circles separate into loose clusters as a D3 force simulation runs. The visualization uses `d3.forceSimulation` with `forceX` pulling nodes toward three distinct horizontal centers, `forceManyBody` for repulsion, and `forceCollide` to prevent overlap. Each of the 100 randomly sized nodes is assigned one of three categories and rendered as an SVG circle whose fill color matches that category. The simulation updates positions on every tick, redrawing the circles via a data join in `index.js`.