This horizontal bar chart displays the 2020 population estimates for 30 countries, with each bar's length proportional to its population value. Built with React and D3.js, the visualization uses reusable components for axes and marks. The `AxisBottom` component generates tick marks with formatted labels, while `AxisLeft` renders categorical labels. The `Marks` component maps each data row to a rectangle positioned by the categorical y-scale and sized by the linear x-scale, with tooltips showing the exact population via SVG `<title>` elements. Data is loaded asynchronously using D3's `csv` parser from a GitHub-hosted CSV file.