There are those who are born able to communicate with the energies surrounding them. While all humans carry a connection to the natural energies, a few select can harness it. Few now, due to the Morsus Adeptus. These are called Magical Talents, or just Talents.
Magic can manifest in various ways.
Three layers of magic has been observed, however it is highly possible that more exist. Talents within the layers can differ greatly, and sub layers can be described. Genereally, however, it is simplified to three.
The Simple Casters, who can harness natural elements in order to produce fireballs, lightnings strikes, and the likes. Simple Casters can also manifest with simple manipulations techniques, of very specific materials, very rarely flesh related.
The Doctors, who has the ability manipulate physical objects. Mostly called doctors, due to many of them using their abilities to heal flesh. This is a notoriously difficult ability to master. You need a perfect knowledge of how the object you intend to manipulate is built up, how it works, and how it can break down.
The Meisters, or masters. The ability to fully harness and manipulate all energies surrounding them. These are rare, and very dangerous. Most of them are living secluded, far away, stereotypically in towers. Those who has not fully mastered their Meister ability run the risk of harming those around them, due to their immense power. Meisters are feared, greatly.
Some theorise that Doctors and Meisters are very much one and the same, with the difference being skill and knowledge. And that some of the Meisters that exist today, were in fact called Doctors in their younger years.
However, those called Meisters do not have to actually learn about an element or object, in order to manipulate it. While the Doctor layer is difficult to master, or even learn within, Meisters instinctivily know about the manipulation process.
Which essentially means that the only difference is that Doctors needs to work harder, in order to obtain Meister status. Though, some Doctors simply do not have the Talent enough, to achieve this.
In some areas and religions magic users, regardless of layer, are considered dangerous and are often simply killed, through burning, impaling, hanging, or other means.