Each person has what is known as a 'magical core'. Whilst this is not something physical and cannot be detected by muggle means, various magical spells and scans have been created to detect ones magical levels - the amount of power in the magical core. Many of these scans however are unreliable and made to be biased and so have fallen out of use with the Medi-wix and Healer community. In the present witches and wizards aren't even scanned for magic levels before entering Hogwarts, whereas in the past this was commonplace.

Very little is taught about the magical core, the centre from which most (though not all) wixen draw their power. It is thought to flow through the body in pathways similar to the veins that carry blood back to the heart and lungs. Depending on how a wix focuses their magic (through a wand, a ring, a headband or diadem, all have been used throughout history) certain magical channels become stronger whilst others wither away. Someone who has no foci, such as an untrained witch or wizard, will find their magical channels develop in a far more rounded way, yet each spell will be less powerful and refined. Such cases of this are often called 'accidental' or 'uncontrolled' magic.

Ones magical core is split into two halves, Light and Dark magic (do not confuse these terms with 'good' and 'evil') which each in turn produce different types of spells, charms, hexes, ect. Though the terms Light and Dark have been used for a long time now, they were originally known as Chaotic and Ordered magic, the terms changing around the 100 A.D. (I will henceforth be using Chaotic and Ordered when referring to the two types of magic.) Evidence suggests that the core is much like the centre of the Earth, with Ordered (Light) magic surrounding a smaller Chaotic (Dark) inner core. As Light magic is the first layer a witch or wizard encounters when accessing their core it is the type most people draw upon. Most spells, whether categorised as 'light' or 'dark' by the Ministry of Magic are primarily composed of Ordered magic.

Ordered Magic was originally named so by the Romans, who are believed to be the first wizards in the Western hemisphere to have begun questioning and understanding magic. This is not to say that other places such as Asia, the America's ect. did not have similar knowledge, but most of our information and magical systems stem from either Rome or Greece. The name is thought to have first been give around 600 B.C and stayed the same for nearly 700 years. 

However it wasn't for another fifty years that Chaos Magic was discovered and named, by a different set of wix who through meditation found there was more to their magical core. It had previously been believed that the whole core was composed of Ordered magic, however as we now know this wasn't the case.