This bar chart displays the 20 most populous countries using data from the United Nations World Population Prospects 2019, with population values shown on a linear scale and countries listed on a band scale. The visualization is built with React and D3.js v5, using scaleBand and scaleLinear for positioning. SVG rectangles represent each country, with native <title> elements providing tooltips, and tick formatting converts values to billions using d3.format with the '.2s' specifier. The chart includes labeled axes for population and styled gridlines.