Sorcery is the most potent and "pure" form of magic, at least according to its practitioners. Other forms of magic generally are another layer on top of sorcery, giving it more shape or altering its properties. It is also known as "Zeale's Gift" because it is impossible for most to "see" and channel the divine chaos necessary for sorcery. Those who can practice it have been directly touched by Zeale and given the capability for it. As such, there have been no new sorcerers since before the Desolation, when Zeale disappeared.
As I am told, sorcery is the act of channeling divine chaos into the mortal realm, and then giving it specific form with exact words, movements, and physical objects. Thus, there are four components that, together, form a specific spell, or effect.
Amount of chaos
So, the first step is to gather chaos. Apparently, reality itself is akin to a massive garment, sewn together with cloth and thread. In the places where the thread has pierced the cloth, there are holes with huge amounts of divine chaos flood through (this is called a leyline). Alternatively, where the cloth is doubled up or folder, little to no divine chaos comes out (this is called a negative leyline). As a result, the efficacy of a sorcerer is largely determined by where they are in the world.
Once the right amount of chaos is gathered, the sorcerer shapes it with a blueprint that can consist of any combination of words, motions, and physical objects.
The difference between an "easy" spell and a "hard" spell is not always the scale of the effects, it may simply be in how many words or how much movement must be performed. Apparently, there is a rather useless spell that creates a small amount of rainbow light which requires a fifteen minute dance to perform!
Performing a spell wrong, whether it's from gathering too much chaos, moving incorrectly, or slurring a word, can have various results. Most of the time, the chaos will simply disperse and nothing will happen. Occasionally, however, a different spell entirely is performed (and this is often how new spells have been discovered over the millennia), or something else forms from the chaos - evil magical creatures have been created in this way!
Sorcery is indeed complex and difficult, and it's no wonder that it was a subject of lifelong study.