This visualization compares COVID-19 total cases across countries on May 1st against May 31st, 2020, using two horizontal bar charts stacked vertically. It highlights which nations had high case counts at the month’s start and end, filtering to countries with over 20,000 cases. The charts are built with the Vega-Lite API, which compiles specifications to Vega, and data is loaded from a CSV file hosted on GitHub using d3.csv. The code uses vl.vconcat to align the two plots and vl.markBar for the bars, with x- and y-encodings sorting by case count.