This visualization shows the number of people who visited various countries using a horizontal bar chart, with country names on the y-axis and visitor counts on the x-axis. The chart renders SVG marks and channels through React components, using D3 scales (`scaleBand` and `scaleLinear`) to position the bars and grid lines. Data is loaded asynchronously from a CSV file via `d3.csv`, and the visualization is updated with React Hooks (`useState` and `useEffect`). The chart includes blue vertical grid lines and green rectangular bars, with axis ticks generated manually from the D3 scales.