A population area chart displays the population of multiple countries from a CSV file hosted on GitHub. The chart uses a single steel-blue filled path created with `d3.area`, positioned by a band scale for countries and a linear scale for population values. Axes from `d3.axisBottom` and `d3.axisLeft` include rotated country labels and axis titles. Data is loaded asynchronously with `d3.csv`, and the SVG renders on a light gray background with a visible border.