This bar chart displays the population of the top 10 most populous countries, using 2018 estimates from the United Nations World Population Prospects 2017. It shows how axis customization highlights data clarity: country names appear on the y-axis, while population values on the x-axis use a custom tick formatter that converts large numbers to abbreviated forms like "B" for billions. Built with D3 v5, the example uses `scaleLinear`, `scaleBand`, `axisLeft`, `axisBottom`, and `tickFormat`. The chart renders as SVG, with gridlines created via `tickSize` and axis labels styled through CSS classes.