The TL;DR version is that the unemployment numbers that tend to get reported are U-3, whereas many people think the U-6 numbers are a more accurate reflection of the real experience.
The U-3 unemployment rate is the most commonly reported rate in the United States, representing the number of unemployed people actively seeking a job. Meanwhile, the U-6 rate covers discouraged, underemployed, and unemployed workers in the country.
https://www.investopedia.com/articles/investing/080415/true-unemployment-rate-u6-vs-u3.asp
Specifically, look into U-3 vs. U-6 unemployment numbers.