The spread for EUR/GBP rises to 0.8532-0.8533 and you decide to sell your euros back into pounds at the bid price of 0.8532. The €10,000 you previously bought is now therefore sold for £8532. Your profit on this transaction is £8532 minus the original cost of buying the euros (£8415) which is £117. Note that your profit is always determined in the second currency of the forex pair.
A single pound on Monday could get you 1.19 euros. On Tuesday, 1.20 euros. This tiny change may not seem like a big deal. But think of it on a bigger scale. A large international company may need to pay overseas employees. Imagine what that could do to the bottom line if, like in the example above, simply exchanging one currency for another costs you more depending on when you do it? These few pennies add up quickly. In both cases, you—as a traveler or a business owner—may want to hold your money until the forex exchange rate is more favorable.
An interesting observation is that the Forex Market Hours of the Tokyo and London sessions overlap for approximately 1 hour (varies for other European countries). You can (and probably should!) use this fact to your advantage. This means that all the crosses of European currencies and the JPY will have the highest volatility at the start of the European session. So if you are trading the GBPJPY you can simply carry out a few powerful trades between 8am-9am GMT, and then you are free for the day!
Risk Disclosure: Trading in financial instruments and/or cryptocurrencies involves high risks including the risk of losing some, or all, of your investment amount, and may not be suitable for all investors. Prices of cryptocurrencies are extremely volatile and may be affected by external factors such as financial, regulatory or political events. Trading on margin increases the financial risks.
The foreign exchange market is the "place" where currencies are traded. Currencies are important to most people around the world, whether they realize it or not, because currencies need to be exchanged in order to conduct foreign trade and business. If you are living in the U.S. and want to buy cheese from France, either you or the company that you buy the cheese from has to pay the French for the cheese in euros (EUR). This means that the U.S. importer would have to exchange the equivalent value of U.S. dollars (USD) into euros. The same goes for traveling. A French tourist in Egypt can't pay in euros to see the pyramids because it's not the locally accepted currency. As such, the tourist has to exchange the euros for the local currency, in this case the Egyptian pound, at the current exchange rate.