Magic In General
To understand magic in the Marvel Universe we must first look at its exact definition.
Magic: The practice of using certain energies and powers whose nature is beyond the scope of technologically oriented science.
The Origin of Magical Power
"Where does all power truly originate? In the long run, from the sun, of course. Here, too, is the indirect birthplace of all mystical might. Control of the source means total control. To be a star means the very laws of nature are yours to amend as you wish. You see, stars are not inert celestial bodies. They are highly intelligent, aware, and powerful."---Apalla, a humanoid form of a star.
"I can't make something out of nothing. Magic is basically a study of forces. Once one knows how to channel these forces, though, the results can be quite striking."---Doctor Strange
Magical power is the life blood of a magic wielder (and of a magical item or creature, for that matter). In the Arcanum of Magic we have seen how magical power is divided into 3 diffrent types: personal, universal, and dimensional. But all magic power is built on common ground, that of reshaping existing power, found in yourself, your universe, or in another dimension, to a form that you desire. What is important to magicians, is the reference to the ultimate power coming from the sun, which is our own star. This may explain why the forces of light, usually referred to as the forces of order, good, or "white", hold sway over the forces of darkness, usually referred to as forces of chaos, evil, or "black". It is this that gives the Doctor Stranges and Shamans of this world their advantage.