By shorting €100,000, the trader took in $115,000 for the short-sale. When the euro fell, and the trader covered their short, it cost the trader only $110,000 to repurchase the currency. The difference between the money received on the short-sale and the buy to cover is the profit. Had the euro strengthened versus the dollar, it would have resulted in a loss.
Most retail Forex traders are in fact day traders, and such traders do tend to generate the highest volumes. Becoming a day trader is an extensive process and once you commit to it, you will have to go through a lot of trial and error. Your discipline, stress resistance, and your confidence in your skills will be put to the test. If you are ready and understand the risks, why not apply for a live account with Admiral Markets and see what day trading is all about?
The foreign exchange market is 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.