Money is anything that is generally accepted as payment for goods and services and repayment of debts. The main functions of money are distinguished as: a medium of exchange, a unit of account, a store of value, and occasionally, a standard of deferred payment.
Money originated as commodity money, but nearly all contemporary money systems are based on fiat money. Fiat money is without intrinsic use value as a physical commodity, and derives its value by being declared by a government to be legal tender; that is, it must be accepted as a form of payment within the boundaries of the country, for “all debts, public and private”.
The money supply of a country consists of currency (banknotes and coins) and demand deposits or ‘bank money’ (the balance held in checking accounts and savings accounts). These demand deposits usually account for a much larger part of the money supply than currency. Bank money is intangible and exists only in the form of various bank records. Despite being intangible, bank money still performs the basic functions of money, being generally accepted as a form of payment.
The use of barter-like methods may date back to at least 100,000 years ago, though there is no evidence of a society or economy that relied primarily on barter. Instead, non-monetary societies operated largely along the principles of gift economics. When barter did occur, it was usually between either complete strangers or potential enemies.
Many cultures around the world eventually developed the use of commodity money. The shekel was originally both a unit of currency and a unit of weight.. The first usage of the term came from Mesopotamia circa 3000 BC. Societies in the Americas, Asia, Africa and Australia used shell money – usually, the shell of the money cowry (Cypraea moneta) were used. According to Herodotus, and most modern scholars, the Lydians were the first people to introduce the use of gold and silver coin. It is thought that these first stamped coins were minted around 650–600 BC.
The system of commodity money eventually evolved into a system of representative money. This occurred because gold and silver merchants or banks would issue receipts to their depositors – redeemable for the commodity money deposited. Eventually, these receipts became generally accepted as a means of payment and were used as money. Paper money or banknotes were first used in China during the Song Dynasty. These banknotes, known as “jiaozi” evolved from promissory notes that had been used since the 7th century. However, they did not displace commodity money, and were used alongside coins. Banknotes were first issued in Europe by Stockholms Banco in 1661, and were again also used alongside coins. The gold standard, a monetary system where the medium of exchange are paper notes that are convertible into pre-set, fixed quantities of gold, replaced the use of gold coins as currency in the 17th-19th centuries in Europe. These gold standard notes were made legal tender, and redemption into gold coins was discouraged. By the beginning of the 20th century almost all countries had adopted the gold standard, backing their legal tender notes with fixed amounts of gold.
After World War II, at the Bretton Woods Conference, most countries adopted fiat currencies that were fixed to the US dollar. The US dollar was in turn fixed to gold. In 1971 the US government suspended the convertibility of the US dollar to gold. After this many countries de-pegged their currencies from the US dollar, and most of the world’s currencies became unbacked by anything except the governments’ fiat of legal tender.