First, the Foreign Exchange Market is generally referred to as FOREX or FX. It is the largest financial network in the whole world with a DAILY average turnover now of over 4 Trillion dollars!!
This is just tremendous growth. Just a few years ago it was under 2 Trillion dollars, and now it is at 4 Trillion and growing.
The largest part of that network is comprised of Banks, governments, and other huge financial institutions, with a smaller part being the retail business (like you and me). When it all add up, the retail customers have the opportunity to enjoy the same trading opportunity as these major institutions. (approx. 10 years ago it was not possible for you and me to trade this market since it was closed).
What is FOREX all about ? It is simply the simultaneous buying of one currency and the selling of another, as I will show you in a moment.
Forex is trading in pairs, For an example, you have the U.S. dollar, Japanese yen pair (USD/JPY) or the Euro,U.S. dollar pair (EUR/USD). The most common, most liquid currencies are referred to as the majors. There are seven currencies, actually six pair as you will see, and those seven currencies are the U.S Dollar,Euro,Japanese yen,British pound, Swiss franc, Canadian dollar, and Australian dollar.
The most commonly traded pairs are as follows: the Euro/US dollar (EUR/USD), the British Pound/US Dollar (GBP/USD), the US Dollar/Japanese Yen (USD/JPY), the US Dollar/Swiss Franc (USD/CHF), US Dollar/Canadian Dollar (USD/CAD), and then Australian Dollar/US Dollar (AUS/USD) pair.
These are the high volume pairs. These are the ones you want to trade. This is where the spread between the bid and ask is smallest. If you get into that they call the exotics where you have different pairings of currencies, the volume drops off with those and the spreads can get rather large and are not nearly as suitable for trading.
The FOREX is a 24-hour market. Actually, from Sunday, 5.00 pm EST, New York (+6 = hours Central European time), to Friday 5.00 pm EST, New York (+6 = hours Central European time), you can actively trade the forex market. Even on the weekend you can make trade (although will not recommend it). The markets do not move on weekend, but your broker would allow you to get in and out of a trade. The sessions start at one point in the world and the rotate around the globe.
The Forex Market is actually an over-the-counter market, meaning no centralized exchange. This means that currencies are traded directly through networks of banks and brokers via electronics network or the telephone. This means the banks and brokers act as their own market makers!!

For day trading (def.: people who open trades and close them on same day – short term), the best hours are shown on below. They are the best hours because the various financial centers around the world will overlap in their trading volume, and during these hours by each of these currency groupings, you tend to get the highest volume and most activity going on in those markets.
You can trade any time around the clock, but I believe these are the best times:
For EUR/USD, GBP/USD, and USD/CHF that would be 3.00 am EST (9 am Central European time), to 3:00 pm (9 pm Central European time).