Economic sector

One classical breakdown of economic activity distinguishes three sectors:^[1]

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.^[2]

Economic theories divide economic sectors further into economic industries.

The built mainly on the basis of subsistence farming.

ancient economy

The lessened the role of subsistence farming, converting land-use to more extensive and monocultural forms of agriculture over the last three centuries. Economic growth took place mostly in the mining, construction and manufacturing industries.

industrial revolution

In the economies of modern , services, finance, and technology—the knowledge economy—play an increasingly significant role.

consumer societies

An economy may include several sectors that evolved in successive phases:

Even in modern times, developing countries tend to rely more on the first two sectors, in contrast to developed countries.

or state sector

Public sector

or privately run businesses

Private sector

Voluntary sector

An economy can also be divided along different lines:

Three-sector theory

Jean Fourastié

Industry classification