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.

The word "economy" can be traced back to the Greek word "one who manages a household", derived from κος, "house", and νέμω, "distribute (especially, manage)". From κονόμος "of a household or family" but also senses such as "thrift", "direction", "administration", "arrangement", and "public revenue of a state".

The first recorded sense of the word "economy", found in a work possibly composed in 1440, is "the management of economic affairs", in this case, of a monastery. Economy is later recorded in other senses shared by κονομία in Greek, including "thrift" and "administration".

The most frequently used current sense, "the economic system of a country or an area", seems not to have developed until the 19th or 20th century.

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.

An informal economy is economic activity that is neither taxed nor monitored by a government, contrasted with a formal economy. The informal economy is thus not included in that government's Gross National Product (GNP). Although the informal economy is often associated with developing countries, all economic systems contain an informal economy in some proportion.