Currencies of the World: Money, Codes and Exchange Rates

A banknote is just a piece of printed paper, and a number on a banking app is just a record. Yet people will work a whole month for them and hand over goods worth thousands. The reason is shared trust: everyone agrees that this paper or number can be exchanged for other things. This article explains what money is, how it developed from shells and coins to cards and phones, how exchange rates and inflation work, what central banks do, and how the rupee fits into the story. A table of capitals and currencies for 135 countries is in Countries, Capitals & Currencies; here the focus is on the money itself.

1.What Is Money?

Money is anything that people in a society generally accept as payment for goods, services and debts. Economists describe three jobs it does.

• Medium of exchange: you can swap it for things you want, without needing to find someone who wants exactly what you have to offer. Without money, trade needs barter, which requires a "double coincidence of wants".
• Unit of account: prices are quoted in it, so goods can be compared. A pen costing Rs 50 and a notebook costing Rs 150 tells you the notebook is worth three pens.
• Store of value: you can save it and use it later, although inflation can reduce what it buys.

Money is also legal tender when a government says it must be accepted for the payment of debts within the country. A currency is a country's (or group of countries') official form of money.

2.A Short History of Money

• Barter and commodity money. Early societies swapped goods directly, and later used items such as cowrie shells, salt and metals as money. Cowrie shells were used across parts of Asia and Africa for many centuries.
• Coins. The oldest known coins come from Lydia, in what is now western Turkey, around 600 BC. Stamped metal solved a problem: a coin's weight and purity were guaranteed by the ruler's mark.
• Paper money. Paper notes first appeared in China, with the Song dynasty issuing paper money in the 11th century. Europe's first banknotes were issued by a Swedish bank, Stockholms Banco, in 1661.
• The gold standard. In the 19th century many countries fixed their currencies to gold and promised to exchange notes for a set amount of it.
• Bretton Woods (1944). At a conference in the United States, Allied countries agreed on a system of fixed exchange rates tied to the US dollar, which was itself tied to gold, and created the International Monetary Fund (IMF) and the World Bank.
• 1971. The United States ended the dollar's convertibility into gold. Since then, the major currencies have been fiat money: valuable because governments declare them legal tender and people trust them, not because they are backed by a precious metal.
• Cards and phones. The first general-purpose charge card, Diners Club, appeared in 1950. Mobile money took off in 2007, when the M-Pesa service started in Kenya, letting people send money by text message.

3.Codes, Symbols and Sub-units

Every currency has a name, a three-letter international code (ISO 4217), often a symbol and a smaller unit. In most codes, the first two letters are the country's code and the third is the first letter of the currency name: PK + R = PKR (Pakistani rupee), US + D = USD (US dollar). The euro, EUR, is shared by several countries and is an exception.

4.Exchange Rates

An exchange rate is the price of one currency in terms of another. It tells you, for example, how many rupees buy one US dollar. There are two broad systems:

• Floating: the rate moves with supply and demand in the market, though a central bank may sometimes step in.
• Fixed (pegged): a government keeps its currency at a set rate against another currency, such as the dollar or the euro. Pegs can be costly to defend.

Rates move because of differences in interest rates and inflation between countries, a country's trade (selling more abroad than it buys raises demand for its currency), investors' confidence and expectations, and political events.

Banks and money changers quote two prices: a buying price and a slightly higher selling price. The gap is the spread, and it is one way they earn money.

The foreign exchange market is the largest financial market in the world, with about $9.6 trillion traded per day in April 2025. The US dollar is on one side of about 89% of trades, followed by the euro, the Japanese yen and the pound sterling.

5.Inflation and Purchasing Power

Inflation is a general rise in prices over time. It means each unit of money buys less. Statisticians measure it by following the cost of a typical "basket" of goods and services and reporting the change as a percentage, usually per year. This is the consumer price index (CPI).

Pakistan has experienced periods of high inflation. In May 2023, the year-on-year rate reached about 38%, one of the highest rates on record for the country, before easing. Very high inflation hurts people on fixed incomes the most.

6.Central Banks and Interest Rates

A central bank manages a country's currency and banking system. Its main jobs are to issue banknotes, to keep prices stable, to act as banker to the government and the banks, and to oversee the financial system. Examples include the State Bank of Pakistan, the Reserve Bank of India, the US Federal Reserve and the European Central Bank. The State Bank of Pakistan began work on 1 July 1948.

The central bank's main tool is its policy interest rate, the rate that influences what banks charge each other and, in turn, what they charge their customers. Raising it makes borrowing more expensive, which tends to slow spending and cool inflation. Lowering it does the opposite. The effects take time, and sometimes policies must balance inflation against jobs and growth.

7.The Rupee: A South Asian Story

• Origins. The word "rupee" comes from the Sanskrit rupya, meaning silver. The ruler Sher Shah Suri introduced a standard silver coin called the rupiya in the 1540s, and later Mughal and British rulers continued the system.
• 1947 and after. At independence, Pakistan first used British Indian notes overprinted for Pakistan, and in 1948 the State Bank of Pakistan began operations and issued Pakistani currency.
• Decimalisation. Until 1961, one Pakistani rupee equalled 16 annas. On 1 January 1961 Pakistan switched to a decimal system: 1 rupee = 100 paisa.
• Exchange rate policy. Pakistan's rupee was linked to the British pound at first, then to the US dollar, and since the early 1980s the rate has been managed or market-driven.
• Other rupees. The rupee is the currency name in India, Sri Lanka, Nepal, Mauritius and the Seychelles. The Maldives uses the rufiyaa. India introduced a special rupee sign (₹) in 2010.
• Digital payments in Pakistan. Mobile wallets such as Easypaisa and JazzCash let people send and receive money by phone, and the State Bank's Raast instant payment system launched in 2021.

8.Shared Currencies

• The euro is used by 21 of the 27 European Union countries as of 2026, after Bulgaria joined on 1 January 2026. Euro notes and coins first entered circulation on 1 January 2002.
• Fourteen African countries use one of two CFA francs, one in West Africa and one in Central Africa, both pegged to the euro.
• Eight Caribbean territories share the East Caribbean dollar.
• Some countries, such as Ecuador and El Salvador, use the US dollar as their official currency.

9.Digital Money

Most money today exists as records in bank computers, not as paper. Debit and credit cards, online banking and mobile wallets move these records. Mobile money services in countries such as Kenya and Pakistan let people without bank accounts send and store money using a phone.

Cryptocurrencies such as Bitcoin, created in 2009 by an unknown person or group using the name Satoshi Nakamoto, are not issued by any government. Bitcoin's supply is capped at 21 million coins and its price has been very volatile. Rules about cryptocurrencies differ widely between countries and change quickly, so always check current official guidance, and treat them as high risk. Many central banks are also studying central bank digital currencies (CBDCs), which would be digital versions of national money.

Real banknotes include security features to resist forgery, such as watermarks, security threads, colour-changing ink, microprinting and raised printing.

10.Myths Corrected

11.Key Terms

12.Common Mistakes

• Thinking money and wealth are the same thing. Money is a tool for exchange; wealth is the goods, land, skills and assets people have.
• Believing that a currency with big numbers on its notes is "strong".
• Forgetting that currencies with the same name (rupee, dollar) have different values.
• Mixing up inflation (prices rising) with a falling exchange rate, although the two can be linked.
• Using an old exchange rate. Rates change every day, so always check a current source.

13.Summary

• Money works as a medium of exchange, a unit of account and a store of value.
• It developed from barter and shells to coins (about 600 BC), paper notes, cards and mobile money.
• Since 1971 the major currencies have been fiat money, valued by trust and law.
• Exchange rates move with supply and demand; the US dollar is on one side of about 89% of currency trades.
• Inflation reduces purchasing power, and central banks use interest rates to try to control it.
• The rupee has a long history, from Sher Shah Suri's silver coin to Pakistan's decimal rupee of 1961 and today's digital payments.

14.Check Your Understanding

Try each question first, then tap it to reveal the answer.

For Teachers and Parents

Suggested activities: run a classroom "barter day" and then introduce a classroom currency to show why money helps; ask students to track the price of three items over a few months and calculate inflation; compare notes and coins from different countries for their security features. Discussion prompts: Why do we trust money? What happens if people stop trusting a currency? Exchange rates and economic figures change constantly, so the numbers in this article are examples or dated snapshots and not live data. Nothing here is financial advice. This article is general education for students up to age 18.