Black magic explained
Black magic is often referred to as a kind of magic that's used to accomplish evil or wicked things. A person normally uses black magic in order to harm somebody. As such, black magic can be used for one's personal and selfish gains.
In most cases, one who does black magic is known as a witch (female) or warlock (male).
The differences as well as similarities between black magic and white magic are often debated if not heatedly disputed, and there are various theories offering explanations that compare and contrast these two types of magic. These theories include the theories of "ALL AS ONE", "NO CONNECTION' and "SEPERATE BUT EQUAL."
ALL AS ONE
With the "ALL AS ONE" theory, all kinds of magic are inherently evil. In short, every type of magic is "black" magic. No white magic or any qualifier that would make a type or kind of magic more on "good" side than other. Among religions in world today that have this opinion include many branches of major religions such as Christianity, Buddhism, Islam, Judaism and Hinduism. According to this view, black magic is generally associated with Satanism.
NO CONNECTION
According to "NO CONNECTION" theory, both white magic and black magic are types of magic. However, they're entirely different from each other. They're different from their foundation, and are also accomplished differently, although both types of magic could achieve effects that are similar. This view is the most often communicated message in fiction stories, such as the popular Harry Potter series.
SEPERATE BUT EQUAL
The "SEPERATE BUT EQUAL" theory states that there's no difference between white magic and black magic. They are essentially same thing. What differs white magic from black magic is in end goals. The majority of today's religions follow this view, as well as those fiction stories that don't believe on "no connection" view.