This example shows a horizontal bar chart of COVID-19 cases by country, displaying the top 20 countries based on population. The visualization uses React to manage state and render SVG elements, while D3 v5 handles data loading via `d3.csv` and scales with `d3.scaleBand` for the y-axis and `d3.scaleLinear` for the x-axis. The chart renders tick marks, labels, and rectangular bars directly as JSX components, with data sourced from a CSV file hosted on GitHub.