Mage are humans who can use magic and draw their magic from either the Demonata, Windows, or being in the Demonata Universe. They are metioned not to be that powerful, but only average compared to a magician
Mages need to chant spells to use most of their magic. While magicians don't need to. The only times a Mage can use magic naturally is if they are in great peril, and even then their powers cannot match that of a Magician .