Forex or Foreign Exchange trading is the largest financial market in the world. It involves all the currencies in the world and is known to exchange over 1.5 trillion dollars everyday. Foreign Exchange market is not centralized unlike the stock market and other financial market. Forex exchanges currencies through electronic networks of banks, individual traders and other financial institutions. All these financial institutions are involved in exchanging currencies all over the world.
Also, the Forex market operates 24 hours a day, making it the most liquid market in the world. Just imagine that at anytime of the day, there will always be buyers and sellers in the Forex market. You yourself are an investor in the Forex market. If you have money in your pocket, it automatically makes you an investor of the currency you are holding.