Please let me know in detail abut the forex and currency trading business?

Answer
It's a way to invest your money kind of like the stock market. You are buying and selling, just like the stock market. But rather than buying and selling the actual currency itself, you are buying and selling the DIFFERENCE in value (aka the exchange rate) between two different currencies.

Best way to get into the Forex is to open a demo account at http://comefollowme.zulutrade.com/Performance.aspx and add some strategies to your portfolio. It's all free, and it's the largest Forex strategy website in the world. I'll post some more links below in my sources.

What's an easy way to trade currency for profit?

I see all these Forex trade currency sites, but I don't get their explanation.
What's an easy way to do it? How much is needed? And what all needs to be done?

Answer
buy low then sell high?