This bar chart displays the top 10 most populous countries using 2018 population estimates from the United Nations World Population Prospects. The visualization uses D3 v5 with SVG rendering, and its horizontal bars are scaled using `d3.scaleLinear` and `d3.scaleBand`. Customized axes include a bottom axis with tick formatting that converts large numbers to abbreviated units (e.g., B for billions) via `d3.format`, and a left axis stripped of its domain line. Gridlines and axis labels are styled through CSS classes, with the data loaded from a CSV file.