The Universe is the extent of everything known by the Deviants. From the Core to The Tail. It is made up of "The Veil" and despite being cloudy and wet it remains in a mostly consistent shape. Veins and Moons are easily mapped out and the Deviants have set up a series of Relays littered around the Universe.
Outside of the Universe is unknown. No ship returns if it breaks through The Veil at the edge of The Universe.