This example presents two interactive visualizations of COVID-19 data. A pie chart displays confirmed cases aggregated by WHO region, while a separate bar chart compares confirmed, death, and recovered counts for the top ten countries. The code uses D3 v7 APIs including `d3.pie`, `d3.arc`, `d3.scaleOrdinal`, and `d3.scaleBand` to render SVG elements. Data is loaded via `d3.csv` from a remote GitHub gist, with legends generated dynamically for both charts.