This visualization displays a line chart of average income over time, using green strokes to connect data points on an SVG canvas. The code loads CSV data from a GitHub gist and maps years to the x-axis and earnings to the y-axis. It employs D3 v5 APIs including `d3.csv`, `d3.scaleLinear`, `d3.axisBottom`, `d3.axisLeft`, and `d3.line` to generate the plot, with gridlines and labeled axes for clarity.