Economic sectors

Main article: Economic sectors

The economy includes several sectors (also called industries), that evolved in successive phases.

* The ancient economy was mainly based on subsistence farming.

* The industrial revolution lessened the role of subsistence farming, converting it to more extensive and monocultural forms of agriculture in the last three centuries. The economic growth took place mostly in mining, construction and manufacturing industries.

* In the economies of modern consumer societies there is a growing part played by services, finance, and technology -- the (knowledge economy).

In modern economies, there are four main sectors of economic activity:[citation needed]

* Primary sector of the economy: Involves the extraction and production of raw materials, such as corn, coal, wood and iron. (A coal miner and a fisherman would be workers in the primary sector.)
* Secondary sector of the economy: Involves the transformation of raw or intermediate materials into goods e.g. manufacturing steel into cars, or textiles into clothing. (A builder and a dressmaker would be workers in the secondary sector.)
* Tertiary sector of the economy: Involves the provision of services to consumers and businesses, such as baby-sitting, cinema and banking. (A shopkeeper and an accountant would be workers in the tertiary sector.)
* Quaternary sector of the economy: Involves the research and development needed to produce products from natural resources. (A logging company might research ways to use partially burnt wood to be processed so that the undamaged portions of it can be made into pulp for paper.) Note that education is sometimes included in this sector.

More details about the various phases of economic development follow. As this process was far from being homogeneous geographically, the balance between these sectors differs widely among the various regions of the world.