Since humans are basically motivated by emotions of love and hate, magic has developed into two forms: one which is motivated to benefit mankind, commonly termed 'white' magic, and the one which is present to injure mankind, termed 'black' magic.
It is usually misconstrued that anyone who successfully practices magic is a witch. This is not true as magic in itself is a practice. Therefore, anyone may learn and use this art in their lives.
The type of magic that asserts your will over someone else in a strong, binding, and permanent way, or which is meant to cause damage, harm, or death is called black magic. These are the kinds of spells that sorcerers use. These purposes are highly unethical, and should be avoided by the Wizards.
The simplest form of black magic is sorcery, in which a certain physical act is performed to achieve a particular result.
One of the reasons for the association of black color is that, much of this art originated in Egypt, called Khem, meaning "black" in ancient times.
This is because the fertile flood-deposited soil of the Nile Delta was dark-colored, in contrast to the barren sands of the surrounding deserts, which were red. Therefore, in Egypt, black was good and red represented evil. Many Egyptians were dark-skinned, reinforcing the color association with their land.
It is the intention of the magician that determines the purpose and alignment, not the associated color. Black magic is not necessarily evil, it's about power and control; power to do things, to control the world, and to dominate others. And just as weapons may be used either in aggression or defense, this form of magic is also the color of protection.
People talking about this art, generally refer to it as being used for selfish purposes. In particular, actions like dominating and manipulating people against their will, compelling people to do things they don't wish to do, working against the best interests of others, intentionally inflicting harm on others called Dark Arts.
Also, threatening, oppressing, controlling, power-tripping, ripping off, etc., are all considered to be practices under the Dark Arts. True Wizards simply do not use magic in this way.
This is most often done at the request of a living relative, who might wish to question a departed soul regarding some important matter, or even seek reassurance that they are happy in the Afterlife.
Disclaimer: This methods are reference purposes only, and does not recommend any of the practices and actions mentioned here.