A horizontal bar chart displays the population of 20 countries from the year 2010, sorted by country name on the y-axis and population on the x-axis. Each bar includes a tooltip showing the formatted population value. The visualization is built with React and D3 v5, using `scaleBand` and `scaleLinear` for axes, with SVG `rect` elements for marks. Data is loaded via `d3.csv` from a remote GitHub gist, with population values converted to numbers and formatted using `d3.format`.