This horizontal bar chart displays the populations of the top 30 countries in the year 2000, sorted by country name. The visualization uses D3.js version 7 to create an SVG bar chart with light green bars, a linear x-scale for population values, and a band y-scale for country names. The code imports data from a CSV file using d3.csv and constructs the chart with modular components for axes and marks. Axis labels are formatted using d3.format to display population values in billions.