A streamgraph visualizes COVID-19 case counts across five continents from January to December 2020, using a silhouette offset layout. The SVG rendering, built with D3 v2 in a React framework, loads data from CSV files for daily and monthly aggregation. Hovering a layer fades others and displays a tooltip with the region, case value, and date. The implementation relies on D3's `layout.stack`, `svg.area`, and time scale APIs, with color encoding based on a sequential orange palette.