This bar chart displays the top 10 most populous countries by 2020 population, using horizontal bars sorted descending. The visualization is built with React components for rendering SVG marks and axes, while D3.js (v5) computes scales, ticks, and number formatting via `scaleBand`, `scaleLinear`, and `format`. Data comes from the UN World Population Prospects 2019 CSV. The chart features custom axis components, tick labels formatted with "B" for billions, and tooltips via SVG `<title>` elements.