A horizontal bar chart displays the population of ten countries, with bar lengths corresponding to population values from a CSV file. The chart uses D3 v5's `d3.scaleLinear` to map population data to pixel widths, `d3.csv` to load the data, and `d3.select` to append SVG rectangles. Bars are fixed at 300 pixels tall, with lengths scaled proportionally to the maximum population in the dataset.