A name and its meanings
South West, and South West corner, are names used for a specific part of Western Australia. The region those names denote has been defined in several different ways. As the names are used now, they usually take in the country immediately south of the Perth metropolitan area and west of the Wheatbelt.
The official region and wider use
The narrowest and most specific of the uses is the official, government-designated South West region. Broader usage is also possible. A wider sense may take in the entire south-western quarter of Australia. In Western Australia the same words may refer to a set of named regions rather than one area.
Regions that carry the name
One named region is the South West Region, a multi-member electorate in the Western Australian Legislative Council. Another is a governmental division made up of local government areas. Southwest Australia is named as a biodiversity hotspot and a botanical and freshwater region. The South West drainage division is a drainage region, and the South West Land Division is a cadastral region for land administration. A South West Seismic Zone is a seismic region.