This example displays a horizontal bar chart of the top 30 countries by 2020 population, using a React component that fetches its data from a CSV file via the `d3.csv` function. The chart is rendered as an SVG, with bars drawn using `d3.scaleBand` and `d3.scaleLinear` to map country names and population values to coordinates. Each bar includes a tooltip that formats the population value using the `d3.format` function (abbreviating to billions). Axis ticks and labels are generated by custom React components, with styles applied via CSS classes.