The currency exchange rate is the rate at which one currency can be exchanged for another. It is always quoted in pairs like the EUR/USD (the Euro and the US Dollar). Exchange rates fluctuate based on economic factors like inflation, industrial production and geopolitical events. These factors will influence whether you buy or sell a currency pair.
Trading on margin refers to trading on money borrowed from your broker in order to substantially increase your market exposure. When opening a margin trade, your broker lends you a certain sum of money depending on the leverage ratio used, and allocates a small portion of your trading account as the collateral, or margin for that trade. The remaining funds in your trading account will act as your free margin, which can be used to withstand negative price fluctuations from your existing leveraged positions, or to open new leveraged trades. The relation between your free margin and other important elements of your trading account, such as your balance and equity, will be explained later. For now, it’s important to understand the meaning of margin in Forex.