This area chart visualizes e-commerce sales from 2009 to 2019, with a smoothed line and filled region beneath it. Using D3 v5, the code employs `scaleTime` and `scaleLinear` for axes, `area` and `line` generators with `curveBasis` for smoothing, and `csv` to load remote data. The SVG rendering includes labeled axes with gridlines and a green title, while CSS styles the chart’s tick marks and area fill.