This example shows a horizontal bar chart of country populations, with a custom tick format that abbreviates large numbers from billions (G) to billions (B). It uses D3 v5’s `scaleLinear`, `scaleBand`, `axisBottom`, and `axisLeft` to position bars and axes, with data loaded from a CSV via `d3.csv`. The axis ticks are formatted using D3’s `format` function and the bars are styled with a blue fill in SVG.