This example shows a horizontal bar chart of the ten most populous countries, using 2020 UN population data. The bars are drawn as SVG rectangles, with a linear x-scale mapping population counts to bar widths and a band scale for country categories. The chart is rendered in React, managing data loading via `d3.csv` and state with `useState` and `useEffect`. The layout reserves fixed margins around the plot area, and the SVG canvas is 960 by 500 pixels. The code highlights the use of a margin object to compute inner dimensions, though the y-axis labels are not rendered.