Economy

The economy is the realized social system of production, exchange, distribution, and consumption of goods and services of a country or other area. A given economy is the end result of a process that involves its technological evolution, civilization's history and social organization, as well as its geography, resource endowment, and ecology, among other factors. These factors give context, content, and set the conditions and parameters in which an economy functions. An economy does not have to be a specific size. An economy can mean the economy of a city (local economy), a country (national economy) or the world as a whole (international economy), provided that it is involved in the production of goods and services.Today the range of fields of study exploring, registering and describing the economy or a part of it, include social sciences such as economics, as well as branches of history (economic history) or geography (economic geography). Practical fields directly related to the human activities involving production, distribution, exchange, and consumption of goods and services as a whole, range from engineering to management and business administration to applied science to finance. All kind of professions, occupations, economic agents or economic activities, contribute to the economy. Consumption, saving and investment are core variable components in the economy and determine market equilibrium. There are three main sectors of economic activity: primary, secondary and tertiary.
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 belong to the history section on this article. As this process was far from being homogeneous geographically, the balance between these sectors differs widely among the various regions of the world.