Economic sector

One classical breakdown of economic activity distinguishes three sectors: One classical breakdown of economic activity distinguishes three sectors: 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 industry related to human services and hospitality. An economy may include several sectors (also called 'industries') 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.