When you trade forex, you're effectively borrowing the first currency in the pair to buy or sell the second currency. With a US$5-trillion-a-day market, the liquidity is so deep that liquidity providers—the big banks, basically—allow you to trade with leverage. To trade with leverage, you simply set aside the required margin for your trade size. If you're trading 200:1 leverage, for example, you can trade $2,000 in the market while only setting aside $10 in margin in your trading account. For 50:1 leverage, the same trade size would still only require about £40 in margin. This gives you much more exposure, while keeping your capital investment down.
Leverage simply allows traders to control larger positions with a smaller amount of actual trading funds. In the case of 50:1 leverage (or 2% margin required), for example, $1 in a trading account can control a position worth $50. As a result, leveraged trading can be a "double-edged sword" in that both potential profits as well as potential losses are magnified according to the degree of leverage used.
In every foreign exchange transaction, you are simultaneously buying one currency and selling another. In effect, you are using the proceeds from the currency you sold to purchase the currency you are buying. Furthermore, every currency in the world comes attached with an interest rate set by the central bank of that currency's country. You are obligated to pay the interest on the currency that you have sold, but you also have the privilege of earning interest on the currency that you have bought. For example, let’s look at the New Zealand dollar/Japanese yen pair (NZD/JPY). Let’s assume that New Zealand has an interest rate of 8% and that Japan has an interest rate of 0.5% In the currency market, interest rates are calculated in basis points. A basis point is simply 1/100th of 1%. So, New Zealand rates are 800 basis points and Japanese rates are 50 basis points. If you decide to go long NZD/JPY you will earn 8% in annualized interest, but have to pay 0.5% for a net return of 7.5%, or 750 basis points.
Knowing where interest rates are headed is important in forex trading and requires a good understanding of the underlying economics of the country in question. Generally speaking, countries that are performing very well, with strong growth rates and increasing inflation will probably raise interest rates to tame inflation and control growth. On the flip side, countries that are facing difficult economic conditions ranging from a broad slowdown in demand to a full recession will consider the possibility of reducing interest rates. 
If you are a rookie trader, you may find yourself asking questions such as 'what is leverage in Forex trading?' and 'how can it be useful?' This article will provide you with answers to these types of questions, together with, a detailed overview of Forex leveraging, its advantages and disadvantages, and a list of possible applications and restrictions.
In forex, investors use leverage to profit from the fluctuations in exchange rates between two different countries. The leverage that is achievable in the forex market is one of the highest that investors can obtain. Leverage is activated through a loan that is provided to an investor by the broker that is handling the investor’s or trader’s forex account.