All currency pairs that involve the US dollar as either the base or counter-currency are called major currency pairs. They include the EURUSD, GBPUSD, and USDJPY, to name a few. Currency pairs that don’t include the US dollar, but include the remaining seven major currencies, are called cross pairs. Examples of cross pairs are GBPJPY, GBPAUD, and AUDNZD.
Most retail investors should spend time investigating a forex dealer to find out whether it is regulated in the U.S. or the U.K. (dealers in the U.S. and U.K. have more oversight) or in a country with lax rules and oversight. It is also a good idea to find out what kind of account protections are available in case of a market crisis, or if a dealer becomes insolvent.

Leverage: Allows you to control bigger sums of money by borrowing from your FX broker so you can boost the profits of a trade. The standard leverage offered by most brokers is 1:50 and it can go as high as 1:500. Using a 1:50 leverage it means that you can control with every $1 from your account $50 in buying power. For example, if you invest $10,000 with a broker that provides you with 1:50 leverage it means that your total buying power is $500,000 (50 x $10,000).
Forex is a portmanteau of foreign currency and exchange. Foreign exchange is the process of changing one currency into another currency for a variety of reasons, usually for commerce, trading, or tourism. According to a recent triennial report from the Bank for International Settlements (a global bank for national central banks), the average was more than $5.1 trillion in daily forex trading volume.