This bar chart displays the top 10 most populous countries for 2020, sourced from the United Nations World Population Prospects 2019. Each bar’s length encodes population using a linear scale, while country names are arranged on a band scale. The visualization is built with React and D3 v5, rendering bars and axes as SVG elements. It includes custom axis components, a formatted tick label that abbreviates billions as "B", and a tooltip showing the exact population value.