Chart by Nathan Yau on FlowingData: https://flowingdata.com/2021/06/08/se...
Special thanks to: Eleanor, Michelle Jia, J, Triple, Thomas. And, of course, our holy father of data storytelling: Hans Rosling.
This data visualization is technically called an "Alluvial Diagram". I might call it a "timeanimated, sorted area chart". Or maybe just "slidey snake chart race thingy."