A horizontal bar chart displays the population of 30 countries in 2020, ordered by country name on the y-axis. A linear x-scale encodes population values, with formatted tick labels converting scientific notation to billions (e.g., “1.40B”). Built with React and D3 v5, the chart uses `scaleBand` and `scaleLinear` for axes, with SVG `<rect>` marks rendered from CSV data loaded via `d3.csv`. Axis ticks are styled with blue lines, and tooltips show the formatted population value on hover.