This example visualizes Covid-19 confirmed cases across nine countries using a horizontal bar chart, where bar lengths encode case counts. The code fetches data from a CSV file and renders the visualization with React and D3 v5, using `scaleBand` for the categorical y-axis and `scaleLinear` for the quantitative x-axis. It manually draws grid lines and axis tick labels via D3’s `select` and mapping functions, while the bars are SVG `<rect>` elements. The visualization is fully controlled by React state, with the chart updating when new data loads, and the rendering is done entirely through SVG within a React component.