A part of a country's or region's commercial, industrial and financial activity, delimited either by public, corporate and private organization of expenditures or by agriculture, manufacturing and service product types.
One classical breakdown of economic activity distinguishes three sectors:
* Primary: involves the retrieval and production of raw-material commodities, such as corn, coal, wood or iron. Miners, farmers and fishermen are all workers in the primary sector.
* Secondary: involves the transformation of raw or intermediate materials into goods, as in steel into cars, or textiles into clothing. Builders and dressmakers work in the secondary sector.
* Tertiary: involves the supplying of services to consumers and businesses, such as babysitting, cinemas or banking. Shopkeepers and accountants work in the tertiary sector. In the 20th century, economists began to suggest that traditional tertiary services could be further distinguished from "quaternary" and quinary service sectors. Economic activity in the hypothetical quaternary sector comprises information- and knowledge-based services, while quinary services include industries related to human services and hospitality. Economic theories divide economic sectors further into economic industries.
