This visualization displays the top 10 most populous countries as horizontal bars, using population data from the United Nations World Population Prospects 2019. The chart uses React with D3 v5 for scales and rendering, employing `scaleBand` for the categorical y-axis, `scaleLinear` for the x-axis, and SVG rectangle marks with native `<title>` tooltips. Population values are formatted with `d3.format`, converting gigabytes abbreviation to billions for axis labels.