This bar chart visualizes the populations of the top 10 most populous countries, based on 2018 estimates from the United Nations World Population Prospects. It demonstrates D3 axis customization, using `d3.scaleLinear` for the population axis and `d3.scaleBand` for country labels, which are abbreviated to their first three letters. The code employs `d3.axisLeft` with a custom tick formatter that converts large numbers into abbreviated units like “B” for billions, and `d3.axisBottom` for the categorical axis. SVGs render the bars in steelblue with a minimal, clean design.