This bar chart displays the top 10 most populous countries using 2018 population estimates from the United Nations World Population Prospects. It demonstrates axis customization using d3.scaleLinear, d3.scaleBand, d3.axisLeft, and d3.axisBottom, including custom tick formatting that converts billions to the letter B. The chart removes default axis lines, adds grid lines via tickSize, and includes styled axis labels and a title. Data is loaded as CSV and rendered as SVG rectangles with steelblue fill.