Forex trading does take place daily, where almost two trillion dollars are moved every day - that is a huge amount of money. Think about how many millions it does take to bring about a total of a trillion and then consider that this is done on a daily basis - if you want to get involved in where the money is, forex trading is one 'setting' where money is exchanging hands daily.
The currencies that are traded on the forex markets are going to be those from every country around the world. Every currency has it own three-letter symbol that will represent that country and the currency that is being traded. For example, the Japanese yen is the JPY and the United Stated dollar is USD. The British pound is the GBP and the Euro is the EUR. You can trade within many currencies in one day, or you can trade to a different currency every day. Most all trades through a broker, or those any company are going to require some type of fee so you want to be sure about the trade you are making before making too many trades which are going to involve many fees.
Trades between markets and countries are going to happen every day. Some of the most heavily trades occur between the Euro and the US dollar, and then the US dollar and the Japanese yen, and then of the other most often seen trades is between the British pound and the US dollar. The trades happen all day, all night, and thought out various markets. As one country opens trading for the day another is closing. The time zones across the world affect how the trading takes place and when the markets are open.
When you are making a transaction from one market to another, involving one currency to another you will notice the symbols are used to explain the transactions. All transactions are going to look something like this EURzzz/USDzzz the zzz is to represent the percentages of trading for the percentage of the transaction. Other instances could look like this AUSzzz/USD and so on. When reading and reviewing your forex statements and online information you will understand it all much better if you are to remember these symbols of the currencies that are involved.