A horizontal bar chart displays COVID-19 case counts per country, with bars ordered by the data’s CSV order. The visualization uses D3 v5’s `scaleBand` for the categorical y-axis, `scaleLinear` for the numeric x-axis, and `axisLeft`/`axisBottom` for gridlines. Data is loaded via `d3.csv` and rendered as SVG rectangles with a steelblue fill, while a clickable “Hello” button triggers a browser alert.