From the introduction of the core rulebook:
The World of Urban Fantasy
Welcome to a world where ancient myths and magical creatures stalk the streets, and where legends peek out from behind facades of the everyday and the commonplace. Many people and places are not as they first appear, and even the familiar has unexpected revelations to offer. Supernatural creatures hide their true faces from humanity, and mysterious cults hoard forbidden knowledge. Magical factions conspire and fight secret wars away from the eyes of the mundane world, while ordinary people are plunged into epic quests. Bustling modern cities harbour tales of heartbreak and heart's desire, depression and elation, secret joys and forgotten mysteries... and reveal the true prices that people set on their souls.
These stories do not take place "a long time ago and far, far away" as with traditional fairytales, but right now, or perhaps tomorrow. Is the woman with the faraway look in her eyes in the next train a swan princess who aches to return to the skies? Is the busker with his tinny harmonica the incarnation of a fabled god of music? Perhaps, in the dreamscapes of a city's restless slumber, they really are.