The origins of what people called "magic" were things that people did that were seemingly unexplainable using conventional scientific methods alone. In Old Siikatal, these abilities were very rare and not very well documented. Often, the knowledge of how to harness magic was hoarded and passed down in secrecy. In Wakhan, however, magic became a much more commonplace thing thanks to the efforts of the Exalted Demiurgos, who taught humans and other sentient species how to bend magic to their will.
However, magic cannot do just anything. For example, magic cannot operate outside of the Aether, its physical confines, and it cannot do drastic things such as breaking the law of conservation of mass-energy. It can, however, make processes that are normally quite difficult, such as cancelling out electromagnetic fields at the microscopic level, cold fusion, and mass-energy conversion much simpler, as a lot of magical techniques actually inadvertently do this at small scales.
Magic, as well as the Aether itself, is inherently tied to the Yongmaek. The limits of what one can achieve using magic is decided wholly by what those who use magic believe it can achieve, and this idea itself is said to fuel the power of sorcerers.
Due to the Aether's complete absence from the realm of Yokea, the inhabitants of Yokea cannot use magic at all.