This example shows how to build a bar chart using fundamental D3.js DOM manipulation, with each bar representing a country’s population. The chart uses `d3.csv` to load data, `scaleLinear` and `scaleBand` for scales, `axisLeft` and `axisBottom` for axes, and SVG rectangles rendered with a pink fill. The code loads a CSV file containing country population figures and maps them to bar widths, demonstrating data binding and enter/append patterns.