The seven interrelated classification structures of the ASGC are:
- Main Structure
- Local Government Area Structure
- Statistical District Structure
- Statistical Region Structure
- Urban Centre/Locality Structure
- Section of State Structure
- Remoteness Structure.
Each of these structures serves a specific purpose and is individually discussed in Chapters 2-8.
In Census of Population and Housing years (e.g. 1996, 2001, 2006), all structures of the ASGC are defined. In intercensal years, only the first four structures are defined.
The Main Structure, the Statistical Region Structure, the Section of State Structure, and the Remoteness Structure cover the whole of Australia without gaps or overlaps. The other structures cover only part of Australia. The structures are hierarchical, with different structures having different numbers of levels (see Table 1). Each hierarchical level is made up of one type of geographical spatial unit. The spatial units at each higher level are aggregations of the spatial units at the previous lower level.