All 16 Boolean Logic Gates

Question

I was doing some reseach and I came across a website that had listed 16 different boolean logic operators. I was wondering if all of them were real, and if so, what do they do.

https://www.researchgate.net/figure/Method-for-implementing-all-16-Boolean-logic-functions-in-a-single-MR-unit-with-a_fig1_303770111