An economy is a system of making and trading things of value. It is usually divided into goods (materials and objects) and services (things people do). An economy assumes that there is a medium of exchange, which, in the modern world, is called 'finance'. This makes trade possible. The alternative – systems of barter – exist only on a very small scale.

To better understand how the economy works, it can be discussed in three sections:

• The primary sector which covers raw products from farming, fishing, and mining, and so on.
• The secondary sector which covers manufacturing of goods.
• The tertiary sector which covers a range of services, provided to people and companies.