A horizontal bar chart displays the populations of the ten most populous countries, with values formatted in billions using axis tick labels. The chart uses d3.csv to load data and d3.scaleLinear, d3.scaleBand, d3.axisLeft, and d3.axisBottom to construct scales and axes, while custom axis styling removes domain lines and applies tick sizing. A d3.format call with a custom replace function converts the "G" suffix to "B" for readability.