A React-based bar chart built with D3 renders United Nations population estimates for 2020, showing the ten most populous countries. The chart uses `d3.scaleBand` for the categorical y-axis and `d3.scaleLinear` for the quantitative x-axis, with SVG rectangles representing each value. Axes are constructed as reusable React components (`AxisBottom`, `AxisLeft`) that map scales to tick marks and labels. Data is loaded asynchronously from a CSV file via D3’s `csv` function, and the visualization updates only after the data is fully fetched.