The Dragon Ball Universe is where several manga series written by Akira Toriyama take place, including Dragon Ball, Neko Majin Z and Dr. Slump.
The Universe featured in manga series by Akira Toriyama, most notably Dragon Ball, is shown as a large ball divided into different sections. At the bottom is the mortal realm, consisting of space and planets including Earth, Planet Vegeta and Planet Namek. This is divided into north, south, east and west quadrants which are overseen by beings called Kais. Above the mortal realm is a mountainous area called Hell, while above that is Other World, home to Snake Way, the planets of the various Kais and an enormous planet called Heaven. As you would expect, anyone who lead an exceptionally good life in the mortal realm will end up in Heaven, while those who did terrible things will end up in Hell.