What do you mean by "black humor" and "cold jokes"?

As an aesthetic form, black humor refers to a kind of abnormal comedy with tragic color, which is extended through some negative teaching materials and makes people laugh.

A cold joke is actually a joke that is not funny at all, a boring joke, but it can achieve the purpose of mental relaxation because it is not easy to understand.

Cold jokes generally go beyond conventional thinking, do not conform to logic and real life, and make people feel dumbfounded.

Although some cold jokes are quite funny, in any case, they will not laugh as much as those who have heard "normal" jokes.