Essence is born from Resonance in the world of flesh that ripples into the Shadow, similar to how a sound is produced when a bell is rung. Similar to oxygen, Essence is invisible even to most spirits, but it is nonetheless a vital component of the Shadow's ecosystem. Resonances carries through to existing Essence and can even help spawn more of it. On places with a vivid Essence, a Locus can form that allows Essence to bleed into the material world.
Spirits are born from Essence motes and hunger for it to strengthen themselves. The Uratha, thanks to their half-spirit nature, utilize Essence to fuel their Gifts. Mages interact with it through the Spirit Arcanum, while some rites of Crúac are rumored to manipulate or generate Essence without the vampire really knowing what is going on. The God-Machine has Angels that power their abilities with Essence. When an Angel Falls, he is cut off from Essence and has to make do with Aether.
- , p.63-64