In the forex market currencies trade in lots, called micro, mini, and standard lots. A micro lot is 1000 worth of a given currency, a mini lot is 10,000, and a standard lot is 100,000. This is different than when you go to a bank and want $450 exchanged for your trip. When trading in the electronic forex market, trades take place in set blocks of currency, but you can trade as many blocks as you like. For example, you can trade seven micro lots (7,000) or three mini lots (30,000) or 75 standard lots (750,000), for example.
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.