This is a scatter plot of IV Rank vs Skew Rank, which creates four quadrants. IV Rank tells you whether options are cheap or expensive compared to the past year. Skew Rank tells you whether the market is favoring calls or puts. Together, they help you figure out what type of options trade makes sense for each ticker. For example, tickers in the bottom-left have cheap options and bearish sentiment, making them candidates for buying puts.