A horizontal bar chart displays the population of the ten most populous countries, using a linear scale for population and a band scale for country names. The x-axis uses a custom tick format that abbreviates large numbers and converts "G" to "B" for billions, while axis lines and ticks are selectively removed via `axisBottom` and `axisLeft`. Data is loaded from a CSV with `d3.csv`, and bars are rendered as SVG rectangles with a padding between them.