Major and Minor Currencies
The seven most frequently traded currencies (USD, EUR, JPY, GBP, CHF, CAD, and AUD) are called the major currencies. All other currencies are referred to as minor currencies. Do not worry about the minor currencies, they are for professionals only. Actually, on this site we will only be covering what we call the Fab Five (USD, EUR, JPY, GBP, and CHF). These pairs are the most liquid and are the only currencies we actually trade.
Cross Currency
A cross currency is any pair in which neither currency is the U.S. dollar. These pairs exhibit erratic price behavior since the trader has, in effect, initiated two USD trades. For example, initiating a long (buy) EUR/GBP is equivalent to buying a EUR/USD currency pair and selling a GBP/USD. Cross currency pairs frequently carry a higher transaction cost. The three most frequently traded cross rates are EUR/JPY, GBP/EUR, and GBP/JPY.
Base Currency
The base currency is the first currency in any currency pair. It shows how much the base currency is worth as measured against the second currency. For example, if the USD/CHF rate equals 1.6350, then one USD is worth CHF 1.6350. In the...