hey..shishir..i have replied and explained that to you at AAE on the day you posted there..do read that man..anyways..here is what i replied to your question "what is forex trade?"

forex is FOReign EXchange market and it is an international foreign exchange market,where money is sold and bought freely and this is typically done via brokers..like in any other exchange marketing..in forex trade as you have asked investors earn profit from foreign currency movements which is always done in currency pairs e.g.the exchange rate of EUR/USD on Aug 26th, 2003 was 1.0857..and assume some investor has bought 100 euros on that date, he would have paid 108.570 U.S. dollars..so it was the profit as a whole cause he invested for euros which got higher as compared to dollars and if he/she withdraws as per dollars he/she will be getting that much profit as per the conversion rate..
if you really want to try in forex you should directly go their website to get started as per your fields of interest by reading on there..good luck..here is the direct linkit is introduction to "how to trade in forex basically)
http://www.forextrading.com/articles/HowToTrade.aspx