what is forex and how do people earn from it?

Of course forex is legal. It's the largest market in the world. Forex simply means foreign currency exchange. You trade your local currency for another country's currency. That's it. Nothing scary or weird. However, investing into a market that you know nothing about is a really strange thing to do. A wise investor would take time to learn about the market and how it works before jumping into anything.

i think in forex, you have to be conservative in dealing, you have to watch bloomberg, aware of global economy, in bloomberg, they you give some info and tips when the best time to trade . keep on researching as there are lot of forex trader outhere, be sure to check their company profile

Forex is very much legal. If you are prepared to take risks, (somewhat similar to stock trading), you can make considerable profit. Like stock trading, forex trading too requires adequate knowledge. First, go through some literature about forex trading. Never give your money to anybody who promises you to make money. My best friend, has caused me a loss of Rs.5000 in stock trading. He just played with my money and caused this loss. He didn't have any responsibility over my money. It is our responsibility to keep our money safe. Isn't it? Avoid this kind of situation.