The same goes for the definitions of High and Low magicks. To a ceremonial magickian low magick is what 'witches' do. To a Witch High Magic is casting a circle and talking with the goddess. Again, neither is wrong, but both are right. These general terms are often the cause of much debate and arguing among those that practice the various paths of Magick.
The Pentagram/pentacle is another issue for debate within the various circles of magick. To me I have simplified it as follows (as it seems to correspond better when crossing 'paths'). The fifth point represents "chi" or energy. This energy when pointed "up" calls upon the gods or the divine. When pointed down it calls to the earth, or the power of ones self. The Satanist with his point down is representative of the humanist aspect of Satanist, the Ceremonial Magickian performing the Banishing rituals of the Pentagram use the point down in order to draw the power of the earth into the ritual. In many rituals that call upon the divine (that have also incorporated the star into the ritual) will have the point up, while the rituals that call upon the elements, or self will have it down. Only the Wiccan seems to always adhere to keeping the point in only ONE direction (up).
There are other aspects of magic which one may find topsy-turvy in definitions. It is best to decide for yourself, which works BEST for YOU. Neither way is wrong, neither way is set into stone (though, when dealing with a specific entity it's best to do it the way they like it...as in calling Satan with a point up may show you his wrath).