Goku is a Saiyan from Universe 7). Universe 7 is the universe where the main Dragon Ball series takes place, and it is the universe that we follow throughout the series. Dragon Ball Super introduced the concept of a multiverse to the official Dragon Ball canon, and Universe 7 was revealed to be the weakest in terms of the development of its mortals power level. Universe 6 is the twin universe of Universe 7, and it also has its own race of Saiyans, Namekians, and the race of powerful beings like Frieza. However, there is no counterpart for Goku, King Cold, or Buu in Universe 6.