Forex, also known as foreign exchange, FX or currency trading, is a decentralized global market where all the world's currencies trade. The forex market is the largest, most liquid market in the world with an average daily trading volume exceeding $5 trillion. All the world's combined stock markets don't even come close to this. But what does that mean to you? Take a closer look at forex trading and you may find some exciting trading opportunities unavailable with other investments.
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.

All forex trades involve two currencies because you're betting on the value of a currency against another. Think of EUR/USD, the most-traded currency pair in the world. EUR, the first currency in the pair, is the base, and USD, the second, is the counter. When you see a price quoted on your platform, that price is how much one euro is worth in US dollars. You always see two prices because one is the buy price and one is the sell. The difference between the two is the spread. When you click buy or sell, you are buying or selling the first currency in the pair.

Let's say a trader has 1,000 USD on their trading account. A regular lot of '1' on MetaTrader 4 is equal to 100,000 currency units. As it is possible to trade mini and even micro lots with Admiral Markets, a deposit this size would allow a trader to open micro lots (0.01 of a single lot or 1,000 currency units) with no leverage put in place. However, as a trader would usually be looking for around 2% return per trade, it could only be equal to 20 USD.

Financial leverage is quite different from operating leverage. Operating leverage of a business entity is calculated as a sum total of the amount of fixed costs it bears, whereby the higher the amount of fixed costs, the higher the operating leverage will be. Combine the two and we get the total leverage. So, what does leveraging mean for a business? It is the use of external funds for expansion, startup or asset acquisition. Businesses can also use leveraged equity to raise funds from existing investors.

The bottom line is that you want to pick carry trades that benefit not only from a positive and growing yield, but that also have the potential to appreciate in value. This is important because just as currency appreciation can increase the value of your carry trade earnings, currency depreciation can erase all of your carry trade gains – and then some. 
Since currencies are traded in pairs, it’s impractical and not very useful to draw a pure USD currency chart. Instead we have the option of drawing (or rather having the software plot for us) a chart of the USDJPY pair, or the AUDUSD pair, since it is only possible to quote a currency in terms of another. On the other hand, there are some forex charts that take weighted average of such currency pairs to derive an overall index for a currency. The famous USD index, is a good example.
Currencies are traded on the Foreign Exchange market, also known as Forex. This is a decentralized market that spans the globe and is considered the largest by trading volume and the most liquid worldwide. Exchange rates fluctuate continuously due to the ever changing market forces of supply and demand. Forex traders buy a currency pair if they think the exchange rate will rise and sell it if they think the opposite will happen. The Forex market remains open around the world for 24 hours a day with the exception of weekends.