This area chart visualizes the cumulative growth of world population from 1949 to 2019, with each bar’s height representing the running total for that year. The visualization uses D3 v5 APIs including `d3.scale.ordinal` with `rangeRoundBands` for the x-axis, `d3.scale.linear` for the y-axis, and `d3.svg.axis` to render tick marks and labels. Data is loaded from a local CSV file, and bars are drawn as SVG rectangles positioned using the ordinal scale’s band width.