This example demonstrates a basic bar chart of population data for ten countries, sourced from a CSV file. It uses D3 version 5 to map population values to horizontal bar widths, with countries positioned along the y-axis. The code imports specific D3 API functions such as `select`, `csv`, `scalelinear`, `max`, and `scaleBand` to handle data loading and scaling, then appends `rect` elements to an SVG canvas, with custom styling via an external CSS file.