This example shows a horizontal bar chart of population estimates for the ten most populous countries, with bar lengths proportional to each country’s population. Using D3 v5, it loads CSV data via `d3.csv`, converts the population values to numbers, and maps them to pixel widths with `d3.scaleLinear`. The chart renders as SVG rectangles appended to the page, each with a fixed height of 300 pixels, demonstrating a basic data-binding workflow with `.data()` and `.enter()`.