Alluvial plots show streams of different colors that show how certain categorical variables interrelate. I am not sure that the graphs are all that effective, but if you want to draw these types of graphs, this page shows a lot of wonderful examples using the structure of ggplot2.
Jason Cory Brunson. Alluvial Plots in ggplot2, 2020-12-04. Available in html format.
An earlier version of this page was published on new.pmean.com.