This bar chart displays 2020 population estimates for 30 countries, sorted along a horizontal axis with country names on the vertical axis. Population values are formatted using the `format('.2s')` specifier, converting billions into abbreviated labels like “B”. The React-based visualization uses `scaleBand` and `scaleLinear` from d3.v5 to map data, with SVG rectangles generated by custom `Marks`, `AxisBottom`, and `AxisLeft` components. Data loads via `d3.csv` from a GitHub-hosted CSV file, and hover effects change bar colors through CSS transitions.