Magic is a supernatural force that can be controlled by certain beings. As far as can be seen, magic ultimately belongs to the Dragons, for they are the source of the weirstones that grant power to the Magical Guilds. However, there is another kind of magic, known as The Old Religion which is briefly mentioned by Nicodemus Snowbeard as "An old kind of blood magic that predates wizardry". All that is known of this kind of magic is a kind of Old Magic, and predates wizardry. However, it can be assumed, based on the way Nick spoke of it, that Anaweir are capable of using it, and it is much like wizardry's own Old Magic.
As stated by Leander Hastings, wizardry is an art and not a science, and thus, the same can be infered of other magics.