This example displays the relative population sizes of ten countries using a full-width rectangular bar chart. Each country’s population is loaded from a CSV file, and the bars are appended to an SVG container via D3’s data join. The chart uses `d3.csv` to parse the data, with population values converted to numbers. All rectangles share a uniform fill color and are rendered at the full width of the inner chart area, showing a simple, unannotated comparison of national populations.