In the right hand path traditions, the words “black magic” are denoted as magic to effect some sort of negative or harmful work. In left hand path traditions, the goal of the work doesn’t determine white or black.
Note: Many modern LHP initiates dismiss the idea entirely of white and black magic – finding the terms to be loaded (and they are loaded with lots of preconceived ideas.)
However, for the purpose of some definition (as the words may appear in the context of this site), I will use a quote from Dr. Stephen Flowers in his compiled work, Dark Runa:
In a precise sense the distinction between White and Black Magic is that White Magic is a methodology for the promotion of union with the universe and pursuing aims in harmony with those of the universe, while Black Magic is such a methodology for the exercise of independence from the universe and pursuing self-oriented aims.Flowers, Dr. Stephen. “Black Runa” pg. 16