The Weave

The Weave is the source of both arcane and divine spellcasting. It is protected and controlled by Mystra Goddess of Magic. In addition to the Weave, there is also The Shadow Weave created by the goddess Shar; because Shar is a goddess of secrets, its secrets are kept mostly to herself.
All magic depends on the Weave, though different kinds of magic access it in a variety of ways. The spells of wizards, warlocks, sorcerers, and bards are commonly called arcane magic. These spells rely on an understanding—learned or intuitive—of the workings of the Weave. The caster plucks directly at the strands of the Weave to create the desired effect. Eldritch knights and arcane tricksters also use arcane magic. The spells of clerics, druids, paladins, and rangers are called divine magic. These spellcasters’ access to the Weave is mediated by divine power—gods, the divine forces of nature, or the sacred weight of a paladin’s oath.
Whenever a magic effect is created, the threads of the Weave intertwine, twist, and fold to make the effect possible. When characters use divination spells such as detect magic or identify, they glimpse the Weave. A spell such as dispel magic smooths the Weave. Spells such as antimagic field rearrange the Weaveso that magic fiows around, rather than through, the area affected by the spell. And in places where the Weave is damaged or torn, magic works in unpredictable ways—or not at alI.