Rules of magic

Although the different magics seem and work in so many different ways, they all deep down follow the same rules and present the same basic characteristics. All of them are presented here:
First off, although magic is everywhere that does not mean that is spread evenly across the cosmos. For example, in Ertoria, there are geographic areas where magic is more or less concentrated, allowing for easier or harder use of spells. It is also important to note that magic is also present in all living beings, integrated into them through their souls. However, most have so little innate magic that for all intents and purposes, is as if they had none.
Second, is connected to the dimension of Pheranor, the realm of souls, demons, and gods. The fact is that areas, where the veil that keeps the material plane and astral plane separated is thinnest, are also the areas where magic is strongest. In Ertoria, the strongest areas of both poles, where raw, pure magic floods into reality like a torrent that very quickly turns into a calm river, as it defuses into both the land, seas, and air.
Third, the main effect of magic is simple: the warping and bending of reality itself. Magic users bend the rules of reality to a greater or lower extent, allowing them to produce feats that defy logic, reason, and/or the natural laws that apply to things in normal circumstances. This warping and bending of natural law explain the ability of magic users, like summoning fireballs in their bare hands out of nowhere, the capability of priests to provoke miracles or curses for their patron's followers or enemies respectively, or in a more "subtle" way, the appearance of beings that would not emerge on a non-magic, completely natural circumstance or area. A noteworthy example of this is the mighty dragons, with natural capabilities that would be unfeasible without the existence and capabilities of magic. That dragons are among the most magical beings in the world, combined that they all originated from magic-heavy areas of Ertoria gives credence that it was magic that explain the origin of these mighty beings.
Now, as for the magic users or wielders, how they achieved this connection is explained here: first off, one's magic is merely the manifestation of the individual connection to this dimension, and how the particular individual interacts with its connection determines which abilities they can wield through it.
However, since individuals tend to reach similar interactions and conclusions in regards to magic, and the fact that few can develop their connection all on their own, is quite common for magic users to learn from other more experienced, trained, and/or learned individuals. This fact has led to the rise of the many 'magic types' that exist in Ertoria. Pyromancy, Astromancy, and many others, all gather individuals with similar characteristics, and often similar goals. A similar thing could be said of priests and devoted religious followers, who gain a connection to magic thanks to their patron god's blessing.
As for non-religious magic wielders, there are two main ways to gain a connection and therefore be capable of wielding magic: one is either born with a connection, or one makes one, either through the use of specially designed artifacts or tools, high dedication to one's art or craft, or more commonly, through pacts with demons, the lesser beings which inhabit Pheranor. These key different ways to magic are the bases for the difference between mages, "artificers", elite and legendary craftsmen or fighters, and sorcerers.