Maori were a communal society, with the welfare of the tribe seen as more important than that of the individual. Although there was family ownership of lands, canoes or other assets, ultimately these all belonged to the iwi as a whole. Tribal names were usually prefaced by the words, Ngati, Ngai, Nga or Ati, all meaning offspring, to the name of the ancestor for whom the iwi was named. For example, Ngati Porou, an East Coast tribe, was formed by descendants of the chief, Pororurangi.

Within each iwi there are many hapu (sub tribes), each with a good number of whanau (family) groupings.