The Australian share market is broken up into 11 Sectors, 24 Industry Groups, 68 Industries and 157 Sub-Industries 1. The ASX has no companies in 9 Sub-Industries. On 16 September August 2016 the 11th Sector "Real Estate" was added - see announcement.
Companies are categorised according to their primary business activity following the Global Industry Classification Standard (GICS). As most established markets use GICS, investors can accurately compare the performance of Australian sectors/industries to those of other countries.
Australia's 11 GICS sectors each have a benchmark index that tracks the performance of ASX-listed companies in that sector.
The constituents of the ASX sector indices are selected from the S&P/ASX 200. As the pool of eligible ASX stocks is relatively small, some sector indices only contain a handful of companies.
Note: Australian investors generally use the term "sector” when discussing a company's activity. Confusingly, it’s common for investors to use the slang term “industry” when they’re actually referring to a company’s “sector”.