Schools of Magic
Whether arcane magic or divine magic, ambient magic or focused magic, the Magic of Krynn falls under one or more categories known as Schools of Magic. Arcane magic (that used by sorcerers, wizards, and similar magical users) generally has a tighter focus on schools than does divine magic (that used by clerics, mystics, and similar people of faith).
Regarding High Sorcery, the three Moons of Krynn are a determining factor in the power of a wizard's spells. Each order receives its powers from one of the moons. Wizards of the White Robes receive their power from Solinari. Those of the Red Robes get their power from Lunitari and those of the Black Robes receive power from Nuitari. The alignment and phases of the moons in the sky determines how effective and accurate a spell is, as well as how many spells a wizard can retain.