This example displays a horizontal bar chart of the populations of the ten most populous countries, using data from a CSV file. The chart ranks countries from largest to smallest, with bars colored steelblue and clear axis labels. It uses D3 v6 APIs such as `d3.csv`, `d3.scaleBand`, `d3.scaleLinear`, `d3.axisLeft`, and `d3.axisBottom`. The code customizes axes by removing domain lines, adding grid lines, and formatting tick labels to show values in billions.