From Camarilla Wiki

Every mage is said to walk a Path, one that leads through a Supernal Realm to a Watchtower. This is not a literal or physical route, but a metaphorical road or direction for the soul. Each realm has its own metaphysical laws that favor some principles over others. These laws are represented by the Arcana and their degree of power within a realm, described as Ruling (the principles represented by the Arcana are manifested in their most pure forms), Common (the Arcana are more powerful than in the Fallen World, but not as pure as the Rulers), and Inferior (the Arcana are still more powerful than in the Fallen World, but they exert little influence over the realm). A mage’s beginning Arcana, the magical lore he knows from his Awakening and immediate studies afterward, tend to be the Ruling Arcana for his realm.