This example displays a horizontal bar chart of the top 30 countries by 2020 population, using SVG rectangles scaled by a linear population axis and a categorical country axis. The visualization loads data from a CSV file and formats population values in billions with D3's `scaleLinear`, `scaleBand`, and `format` utilities. React components render the axes and marks, with tooltips provided by SVG titles and blue axis ticks styled via CSS. The chart highlights D3 v5 integration within a React framework, demonstrating basic data loading and declarative chart construction.