The combination of currency that is used is called cross. The trades that are immediately settled is the spot market, this is because they are settled “on the spot”. This has the most volume and in the Forex trading  market it is most important. Two banking days is what is meant by immediate.
When you trade on margin this means that you can sell and buy assets representing more value than the capitol that you have in your account. Since the margin deposits are usually relatively small this can be useful to the investor. You can make a lot of profit fast but your risk is greater.

No matter what market is used when it comes to stocks there is always a chance that you can lose your money. The best thing to do to prevent this is to research the stocks that you might be interested in before you purchase them.