This example visualizes the top 10 most populous countries in 2020 using a horizontal bar chart, with country names on the y-axis and population values on the x-axis, formatted in billions. The visualization is built with React components and D3.js v5, using `scaleBand` for the categorical axis, `scaleLinear` for the numeric axis, and SVG `rect` elements to render the bars. Data is loaded from a CSV file of the United Nations World Population Prospects 2019 via D3’s `csv` function, and tooltips appear on hover via native SVG `title` elements.