A bar chart displays the 2020 populations of ten countries using D3.js v7 scales, with country names on the y-axis and population magnitudes on the x-axis. React components—AxisBottom, AxisLeft, and Marks—render the SVG axes and horizontal rectangles. The data loads from a CSV via `useData` and `d3.csv`, while `scaleBand` and `scaleLinear` map values to pixel coordinates.