A vertical bar chart displays the top 10 most populous countries based on UN Population data for 2020, with the population values encoded by bar length on a linear scale and countries ordered along a categorical band scale. D3’s `scaleLinear` and `scaleBand` position the marks, while `format('.2s')` converts large numbers to readable abbreviations like “B” for billions. Tooltips expose exact values on hover. The React-based implementation separates axes and marks into reusable components, applying SVG rendering with margins and external Poppins font styling.