This bar chart displays the population of the top 10 most populous countries, using 2018 estimates from the United Nations World Population Prospects. The axes are customized through D3’s `scaleLinear`, `scaleBand`, `axisLeft`, and `axisBottom` APIs, with tick formatting converting values to billions. The bottom axis includes a label and the chart is rendered as SVG, with bars drawn as `rect` elements. The code removes default axis lines and ticks, and the visualization omits the left axis line for a cleaner design.