This example demonstrates how to build a bar chart from a CSV file of country populations using D3.js. The visualization maps each country to a rectangle, with bar heights proportional to population values, rendered as SVG elements. The code uses D3's `select` and `csv` functions, importing data from `data.csv` and logging it to the console. The chart is created within an SVG canvas sized 960 by 500 pixels, with the styling handled by an external stylesheet.