This bar chart displays the 2020 population estimates for 30 countries, with a green horizontal bar for each nation ordered along a categorical y-axis. The chart uses a linear x-scale to encode population values, formatted with D3's `format('.2s')` to show billions with a "B" suffix. It is rendered as SVG in React 16, using `d3.csv` asynchronously loaded from a GitHub-hosted dataset, while `d3.scaleBand`, `d3.scaleLinear`, and `d3.max` calculate scales from the data.