This example displays world population from 1950 to 2015 as a smooth area chart, using a time-scaled x-axis and a linear y-axis. The chart is rendered with SVG, and the area path is generated using `d3.area` with `curveBasis`. Axes are created via `axisBottom` and `axisLeft`, with population values formatted in billions. Data is loaded from a CSV using `d3.csv`, with years parsed as dates and population values multiplied by 1000.