This question is somewhat vague (for instance, what is "true nature" and "commonly understood"), but I'll give it a go.
As a general rule, the way that things outside the immediate material realm work are somewhat different from what is commonly understood, because we as people have difficulty grasping them. (In fact, we as people also have difficulty grasping things that are very large or very small, even in the material world.) So with respect to the way these things work, what is commonly understood (or even ever understood by the vast majority of people) is lacking.
There are some videos on YouTube, etc, these days, by Muslims (usually, Salafis) claiming to talk about how black magic is done, signs of black magic, etc. These videos are true in some ways and not true in other ways. So it is best to be skeptical about them, or not watch them at all.