If every single country the entire world over all had the exact same currency, say the United States Dollar or the British Pound, when you traveled, you would never need to exchange your currency. You would not have to worry about an exchange at all because if every country used universal money, it would not matter.
But the world's currency differences among countries, which gives reason for the Foreign Exchange (or the Forex as it's more commonly referred to). The Forex is where all the currency trading is handled. How does the Forex come in handy when you're dealing in any type of exchange of one country's money for another's? The Forex is used to trade one currency for another.
Without it, if you turned all your United States Dollars into say, Japanese Yen, but came back to the United States with the equivalent of $ 1,000 tied up in yen, the yen would be worthless to you here. You could not exchange that yen at any fast food restaurant. You could not shop for clothes with it, you could not rent a motel room.
Without currency exchange facilitated through the Forex, you could end up hungry and naked and without a place to sleep. Okay, that's a drastic example, but money really is the oil that makes the entire world go around.The Forex is the machine that the oil is funneled through.
One can not work without the other. If there was no Forex, travel out of and to the United States could very well ground to a halt. Can you imagine a world without the ability to exchange money? Without the Forex, that imagined world would become very real indeed.
Exchange with the Forex is not limited to just small time investors, traders who operate out of their home and it's not just limited to well heeled investors who make millions. The Forex is for anyone with a need to exchange currency.
The Forex is also used by multi-million dollar corporations. If a company here in the United States does business outside the US and pays a foreign company for a product or service, there must be a way for that currency to exchange from United States Dollars to whatever currency is used in the foreign country. As long as there is money that needs an exchange from one country to another in order to be used, there will always be a need for the Forex.