what is forex?

FOREX, or Foreign Exchange, is buying and selling of currencies. The US dollar is almost always the base currency against which other currencies are bought and sold. also referred to, as “FX” is open to corporations, small businesses, commercial banks, investment funds and private individuals
As far as the freedom from any external control and free competition are concerned, FOREX is a perfect market. FOREX is a more objective market, because if some of its participants would like to change prices, for some manipulative purpose, they would have to operate with tens of billions dollars. That is why any influence by a single participants in the market is practically out of the question. The superior liquidity allows the traders to open and/or close positions within a few seconds.

However, Forex is not a market in a traditional sense. It doesn't have a fixed location of the trading floor as, for example, futures market does. The trading is done over the telephone and at the computer terminals in hundreds of banks around the world simultaneously
The most commonly traded currencies are referred to as “Majors”; over 85% of daily transactions on Forex trading involve the Majors. These seven currencies are the US Currency (Dollar, USD), Japanese Yen (JPY), Euro (EUR), British Pound (GBP), Swiss Franc (CHF), Canadian Dollar (CAD) and Australian Dollar (AUD).
The time of keeping a position is arbitrary and has no limits: from several seconds to many years. It depends only on your trading strategies. Although the daily fluctuations of currencies are rather insignificant, you may use the credit lines, that are accessible even to currency speculators with small capitals ($ 1,000 - 5,000), where the profit may be impressive.
Forex is open 24 hours a day, and the currency exchange operations are maintained throught working days of the week. Almost every time zone (London, New York, Tokyo, Hong Kong, Sydney) has dealers willing to quote currencies
This market surpasses the others in its volume. For example, the daily turnover of world securities market is estimated at $300 billion, while Forex approaches 1 to 3 TRILLION US dollars in the same amount of time