This example displays a horizontal bar chart of the top 12 countries by population in 2020, with country names on the y-axis and population values on the x-axis. It fetches CSV data from a GitHub URL using `d3.csv` and parses the population column as numbers. The chart renders as an SVG using React components, while D3 utilities `scaleBand` and `scaleLinear` compute the positions and widths of the bars, and `ticks()` generates the axis tick labels. The visualization demonstrates integrating React’s state management with D3’s data manipulation and scaling APIs.