This bar chart visualizes the populations of ten countries, with bar width proportional to each country’s population in thousands. Built with D3.js v5, it uses `d3.select` to target the SVG, `d3.csv` to load the data, and `d3.scaleLinear` with `d3.max` to map population values to pixel widths. Each bar is a `rect` appended via `enter()`, with a fixed height of 300 pixels. The data comes from a local `data.csv` file, rendered as an SVG graphic.