This line chart displays website traffic by source, showing the number of visitors for each source alongside a monotone-smoothed trend line. The implementation uses D3 v7 with an SVG canvas, reading data from a CSV file. The visualization employs `d3.scaleLinear` for both axes, `d3.axisBottom` and `d3.axisLeft` for labeled axes with rotated source labels, and `d3.line` with `d3.curveMonotoneX` to render the smoothed path. Gridlines are added via a dashed `d3.axisLeft` layer.