This visualization depicts the cumulative number of COVID-19 deaths across various countries, plotted against the number of days since each country recorded its tenth death. The chart uses multiple lines, color-coded by country, with a legend to identify each one. The data is processed from CSV files, and the visualization is built with D3 v5, using scales like `scaleLinear`, axis functions, and the `line` generator to create the paths. The code also includes custom logic for data cleaning and merging the datasets.