Most individuals in Central Australian Aboriginal society are members of a subsection or skin group. Memberships of a particular subsection is normally determined by parents skins, although there is scope for a skin to be assigned for an outsider, or non-aboriginal person.

The skin system is essentialy a broad grouping of kin, including many people who are only distantly or notionally related. Through the skin, it is possible to calculate ones notional relationships with others, and each skin collects together a particular set of relations. For example: a man’s own skin group includes his brothers and sisters, father’s father (and his brothers and sisters), sons children, and brother’s son’s children. The skin system also determines social systems: proper behaviour (avoidence, respect, familiarity) rights and responsibilities, as well as ceremonial and land tenure relationships.

In central Australia, the normal subsection system consists of eight skins, as it is in the case with the Arrente, Warlpiri, Pintupi/Luritja; the latter two taking the additional step of marking the different sexes. Groups neighbouring these three usually follow a similar system except that some such as the Pitjantjatara and other Western Desert families, make use of a six section system, whilst Alyawarra in the north-east uses four.