Economic activities are classified into three main sectors: primary, secondary and tertiary.
+The primary sector includes the activities based on the extraction of goods and resources from the environment: agriculture, stock breeding, hunting, forestry, fishing and mining. Primary activities are carried out in rural, marine and forest areas, which are usually far from the cities.
The primary sector of the economy extracts or harvests products from the earth. The primary sector includes the production of raw material and basic foods. The packaging and processing of the raw material associated with this sector is also considered to be part of this sector.
In developed and developing countries, a decreasing proportion of workers are involved in the primary sector.
+ The secondary sector includes the economic activities which transform the goods and resources extracted from the environment (raw materials) into processed products. Construction and industry are the main activities in this sector.
Industries are usually located in cities and nearby areas.
The secondary sector of the economy manufactures finished goods. All of manufacturing, processing, and construction lies within the secondary sector. Activities associated with the secondary sector include metal working and smelting, automobile production, textile production, chemical and engineering industries, aerospace manufacturing, energy utilities, engineering, breweries and bottlers, construction, and shipbuilding.
+ The tertiary sector includes activities which provide services of all kind: trade, transport, tourism, health, communication, education, finance or culture.
The tertiary sector of the economy is the service industry. This sector provides services to the general population and to businesses. Activities associated with this sector include retail and wholesale sales, transportation and distribution, entertainment (movies, television, radio, music, theater, etc.), restaurants, clerical services, media, tourism, insurance, banking, healthcare, and law.
In most developed and developing countries, a growing proportion of workers are devoted to the tertiary sector. In the U.S., more than 80% of the labor force are tertiary workers.
+ The quaternary sector is due to the rapid expansion of the tertiary sector. It includes several service activities characterised by a high level of specialisation, such as management, decision-making, high research or the new technologies. The quaternary sector of the economy consists of intellectual activities. Activities associated with this sector include government, culture, libraries, scientific research, education, and information technology.
+ The quinary sector
Some consider there to be a branch of the quaternary sector called the quinary sector, which includes the highest levels of decision making in a society . This sector would include the top executives or officials in such fields as government, science, universities, nonprofit, healthcare, culture, and the media.
An Australian source relates that the quinary sector in Australia refers to domestic activities such as those performed by stay-at-home parents or homemakers. These activities are typically not measured by monetary amounts but it is important to recognize these activities in contribution to the economy.