ISO 4217 has been an international standard established by ISO to defined currencies of different countries. The need for such standardization was felt when it was realized that some of the names of currencies like dollar, pounds and franc are used in many different countries and all have different values in the market. So, by giving a designated code to all the currencies, one cannot get confuse one currency with the other.
The ISO 4217 standard also defines a relationship between major currency unit and its minor currency unit which can be 1/100, 1/10 or 1/1000 of the major unit. Some currencies do not have any minor unit of currency at all like Mauritania. Not only currencies, the ISO 4217 standard is also used for valuable metals such as gold, palladium, platinum and silver and some other entities of international finance like Special Drawing Rights. With this code, forex trading becomes easier and confusion-free and there are less chances for the traders to make silly mistakes.